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Cisco BTS 10200 Softswitch

H.323 Provisioning, Operating, and Troubleshooting Guide

Table Of Contents

H.323 Provisioning, Operating, and Troubleshooting Guide for the
Cisco BTS 10200 Softswitch, Release 5.0

Contents

Overview

Cisco BTS 10200 Softswitch in the H.323 Packet Network

Summary of H.323 Capabilities

Interoperability with Cisco CallManager and Other Endpoints

Prerequisites for Interoperability

Limitations on Interoperability

Annex E UDP Functionality

Restart and Failover Scenarios

Limitations on Annex E Support

Message Tunneling and Protocol Transparency for H.323-Based Transit Traffic

Reattempt, Route Advance, and Hairpinning (Redirection)

Reattempt and Route Advance on H.323-Based Calls

Hairpinning (Call Redirection) on H.323-Based Calls

T.38 Fax Support over H.323

Supported Interfaces and Interworking

T.38 Fax Call Features

T.38 Glare Handling

End-to-End SDP Exchange for T.38 Media and the H.323 Interface

Provisionable Parameters for T.38 Fax Over H.323

Additional H.323-Related Features

Planning

Planning for Redundant Operation of H.323 Links

Prerequisites for H.323 Networks

Video Phones

Networks with GKs

Networks Without GKs (Direct Routing)

Restrictions and Limitations

Interoperability with Other H.323 Endpoints

Functionality Related to Video Phones

Functionality Related to ATA Clients

Interoperability Data for Cisco IOS GWs, Cisco CallManager, and MGCP GWs

Installing

Configuring

Provision H.323-Based TGs, Logical GWs, and GKs

H.323-Based Logical GWs Internal to the Cisco BTS 10200 Softswitch

Prerequisites

Provision H.323-Based Video Phone Terminals and Subscribers

Prerequisites

Provision H.323-Based Outbound Routing Data

Understanding the Outbound Routing Process

Outbound Routing Option Summary

Outbound H.323 Calls

H.323 Tandem Calls with Circuit Info Sent

SS7-originated Calls Retransmitted as Outbound H.323 Calls with Circuit Info

Provision H.323-Based Inbound Routing

Provision ANI Screening and Routing

ANI Screening vs. ANI-Based Routing

Identification of H.323 Terminal Property Based on ANI

ANI Screening

ANI Screening on Incoming Calls

ANI-Based Routing

Provision for Interoperability with Cisco CallManager

Assign a Main Subscriber ID when Cisco CallManager Is Used as a PBX

Provision QoS Codec

Disable GTD

Provision Annex E Functionality

Provision Additional H.323 Options

H.323 Protocol Transparency Functions

H.323-Based T.38 Fax Parameters

Additional Advanced H.323 Features

Example of Provisioning Script

Operating

Billing

Identifying Call Legs as Video-Enabled

Billing Data Generation for Video Calls

Billing Records for Calls to/from Cisco CallManager

Updated Billing Field Descriptions

Measurements

Events and Alarms

Announcements

Link Failure Recovery Process

Dual Links for H.323 Signaling Transport

Automatic Recovery Process When GWs are Registered to a GK

Automatic Recovery Process When No GK Is Used (Direct Routing)

Troubleshooting

Outgoing Trunk Group is Out of Service

Solution

Outgoing H.323 Gateway is Out of Service

Solution

H.323 Gateway Fails to Register with GK (Invalid Alias)

Solution

Outgoing H.323 Gateway Unregistered with GK and Needs to Use RAS

Stable Calls Are Dropped When CA Switches Over

No Matching Dial Plan Found on Incoming H.323 Trunk Group

Solution

Configuration at Softswitch or Gatekeeper Has Placed Routing into a Loop

Solution

Outgoing H.323 Calls Routed to Incorrect Endpoint When Using RAS

Solution

Outgoing H.323 Calls Routed to Incorrect Endpoint When Using Direct Signaling

Solution

RAS Still Used When Outgoing H.323 Call Is Provisioned to Use Direct Signaling

Solution

References

Interoperability Data for Cisco IOS, Cisco CallManager, and MGCP

Related Documents

Industry Standards


H.323 Provisioning, Operating, and Troubleshooting Guide for the
Cisco BTS 10200 Softswitch, Release 5.0


This document describes how the Cisco BTS 10200 Softswitch implements H.323 interfaces and functions in Release 5.0. It also provides H.323 provisioning, operating, and troubleshooting procedures.


Note H.323 applications are supported in Release 4.5.1, but not in Release 4.5.0.


Feature History

Release
Modification

Release 5.0

Document OL-12219-02

Procedure to provision the ANI screening on incoming calls were added in the "ANI Screening on Incoming Calls" section.

Release 5.0

Document OL-12219-01

Information about the Overload Control feature, as it pertains to BTS 10200 operation with H.323 networks, is included.

Release 4.5.1

Document OL-8300-03

Corrections were made to the description of call-setup behaviors in the "Limitations on Annex E Support" section

Document OL-8300-02:

Improvements were made to the wording for readability; no technical changes were made.

Document OL-8300-01:

Information about the reattempt, route advance, and hairpinning (redirect) functions was updated and enhanced. A new token (SEND-FS-CALLP) was added in the H.323 Trunk Group Profile (h323-tg-profile) and H.323 Terminal Profile (h323-term-profile) tables to control sending of the Fast Start parameter. Previously (in Release 4.4.1 and earlier), this functionality used the MISC-UNSUPP token.

T.38 fax functionality was enhanced:

Descriptions of the enhancements were added.

Tokens for T.38 fax functionality (in the h323-tg-profile and h323-term-profile tables) were changed. The FAX_T38_GWMODE_SUPP and FAX_T38_CAMODE_SUPP tokens were deleted, and the REMOTE-FAX-PORT-RETRIEVAL-MSG token was added.

In the QoS table, the FAX-PREF-MODE token was deleted and the FAX-T38-ENABLED token was added.

New information was added on fax procedures, limitations, and prerequisites.

The sample provisioning script was updated.

Release 4.4.1

Document OL-7280-05:

A note was added to the "Call-Proceeding Message Transparency" section to clarify the applicability of this parameter to certain call scenarios.

Document OL-7280-04:

Information was added about the dual IP addresses for H.323 signaling, including a section in the "Planning" section explaining how to set up dual links, and a section in the "Operating" section explaining the link-failure recovery process.

Throughout the document (a correction from Release 4.2)—Corrected the provisioning for call-connect-mode and h245-tunneling. Call-start-mode (in h323-gw table) was moved to the h323-tg-profile and h323-term-profile tables and changed to call-connect-mode. H245-tunneling was also moved from the h323-gw table to the h323-tg-profile and h323-term-profile tables. The requirement for placing the H.323 GW OOS and INS is deleted.

Document OL-7280-03: Applicability to Release 4.4.1 was clarified.
The document title and introduction were modified for clarity.

Document OL-7280-02: References were included to the Cisco BTS 10200 Softswitch Provisioning Guide and Cisco BTS 10200 Softswitch Command Line Interface Guide.

Document OL-7280-01:

All H.323 descriptions and procedures were reorganized into one document.

Information was added on the relationship between H245-TUNNELING and FACILITY-SUPP tokens.

Details were added to the route-advance description.

Release 4.2

The following enhancements were provided in this release:

Support for video capability on H.323-based subscriber phones

Support for video on H.323-based trunk groups

H.323 routing enhancements for inbound and outbound call legs

Route advance, reattempt, and redirection

ANI-based screening and routing enhancements

Additional H.323 and video-related billing records

Enhanced interoperability with other endpoints, including Cisco CallManager, using H.323 protocol interface

Improved message tunneling and protocol transparency for H.323-based transit traffic

Additional H.323-related feature enhancements

Release 4.1

Annex E UDP capability was introduced.

Release 3.2

H.323 signaling was introduced on the Cisco BTS 10200 Softswitch.


Contents

This document contains the following sections:

Overview

Planning

Installing

Configuring

Operating

Troubleshooting

References

Overview

This section provides technical information about the implementation of H.323 features. It covers the following topics.

Cisco BTS 10200 Softswitch in the H.323 Packet Network

Summary of H.323 Capabilities

Interoperability with Cisco CallManager and Other Endpoints

Annex E UDP Functionality

Message Tunneling and Protocol Transparency for H.323-Based Transit Traffic

Reattempt, Route Advance, and Hairpinning (Redirection)

T.38 Fax Support over H.323

Additional H.323-Related Features

Cisco BTS 10200 Softswitch in the H.323 Packet Network

The Cisco BTS 10200 Softswitch provides native H.323 signaling, which allows it to communicate directly with H.323 gatekeepers (GKs) and gateways (GWs). The Cisco BTS 10200 Softswitch can be configured as up to four logical H.323 GWs. The Cisco BTS 10200 Softswitch H.323 subsystem includes H.225 and registration, administration, and status (RAS) signaling control, and H.245 connection control. The Cisco BTS 10200 Softswitch also provides signaling for other trunks and lines over Media Gateway Control Protocol (MGCP) and Session Initiation Protocol (SIP). In addition, the Cisco BTS 10200 Softswitch provides access to the public switched telephone network (PSTN). It communicates with IP transfer points (ITPs) that act as signaling gateways (SGs) for SS7-based networks, and with the trunking gateways (TGWs) that provide the bearer path. The details of these signaling links are shown in Figure 1.

Figure 1 Signaling Links with the Cisco BTS 10200 Softswitch and Cisco CallManager


Note For a more complete description of all Cisco BTS 10200 Softswitch features, refer to the Cisco BTS 10200 Softswitch System Description and the Network and Subscriber Feature Descriptions document.


The Cisco BTS 10200 Softswitch H.323-based functions can be used on managed H.323 networks that contain the Cisco BTS 10200 Softswitch and the following network element types:

H.323-based IP PBX systems, including Cisco CallManager

Analog phones connected to customer premises equipment (CPE) such as integrated access devices (IADs)

H.323 primary rate interface (PRI) GWs

H.323 IP-to-IP GWs

H.323-based GKs

H.323-based video phones

H.323-based audio phones


Note The above list is intended as a general summary. For interoperability with specific types and models of external devices, see the Cisco BTS 10200 Softswitch Release Notes.



Note The following terminology is used throughout this document for reference to connection methods described in ITU-T Recommendation H.323, Packet-based multimedia communications systems, Draft v4 (11/2000):

     - Fast-start refers to fast-connect procedures.
    - Slow-start refers to non-fast-connect mode.


Summary of H.323 Capabilities

The following H.323 features and services are provided:

Support for video capability on H.323-based subscriber phones, including video-related billing records.

Support for video on H.323-based trunk groups.

Provisionable routing options for inbound and outbound H.323-based call legs.

Provisionable ANI-based screening and routing options.

Interoperability with other endpoints, including Cisco CallManager, using H.323 protocol interface.

Message tunneling and protocol transparency for H.323-based transit traffic.

Additional H.323-related feature enhancements, such as asymmetric codec resolution, media cut-through, and empty capability set handling.

Support for reattempt and route advance. If a call does not complete, the Cisco BTS 10200 Softswitch can reattempt the call based on the release cause code. The call can be reattempted to the same trunk group (reattempt) or to another trunk group (route advance).

Support for hairpinning (call redirection). On an incoming PSTN call, if the GK cannot route the incoming call, or if the GK determines that the call termination is on PSTN, the Cisco BTS 10200 Softswitch can send the call back out to the PSTN (hairpinning) or to another H.323 call leg (redirection).

Support for modem/fax passthrough. The Cisco BTS 10200 Softswitch allows MGCP GWs and H.323 GWs to transmit and receive faxes using in-band signaling mode. In this mode, the CA treats this call as it would any voice call, and does not perform any T.38 signaling.

Support for T.38 CA-controlled mode. In this mode, the Call Agent (CA) instructs the gateway to switch to T.38 fax mode in real time. The CA receives a signal (Request mode) when fax signaling starts and stops. To enable interworking between networks, the Cisco BTS 10200 Softswitch maps the fax messages according to the protocol (MGCP or H.323) used for the originating and terminating messages. Billing records are generated in the CA based on fax start and stop signals. For additional information on interoperability for various subscriber features, see the "Interoperability Data for Cisco IOS, Cisco CallManager, and MGCP" section.

The Cisco BTS 10200 Softswitch supports the following signaling capabilities:

Information request response (IRR)—When a GK sends an information request (IRQ) message to an H.323 gateway, the gateway responds with an IRR message. IRRs contain per-call information. Cisco BTS 10200 Softswitch GWs can pack multiple call block information messages inside a single IRR message, thereby reducing network traffic. The service provider can provision the CA-CONFIG table for the number of call blocks to pack into a single IRR message.

Resource availability indicator (RAI)—The RAI is sent by a GW to a GK to indicate a change in resource availability. The service provider can provision three fields in the H323-GW table to control the RAI behavior of the Cisco BTS 10200 Softswitch:

MAX-VOIP-CALLS—The total number of calls a Cisco BTS 10200 Softswitch H.323 gateway will support.

HIGH-WATER-MARK—A percentage of the MAX-VOIP-CALLS. Once this level is reached, the Cisco BTS 10200 Softswitch sends an RAI with outOfResources=TRUE.

LOW-WATER-MARK—A percentage of the MAX-VOIP-CALLS. Once this level is reached, the Cisco BTS 10200 Softswitch sends an RAI with outOfResources=FALSE.

Calling number information delivery (Octet 3A)—The Cisco BTS 10200 Softswitch delivers calling number information (such as calling number, presentation restrictions, and so forth) to the terminating H.323 GW via a Cisco proprietary octet 3A field in the H.323/H.225 setup message.

Alternate GK capability—If the preferred GK becomes unavailable, the Cisco BTS 10200 Softswitch can contact alternate GKs on a provisionable list. But if the preferred GK is found using multicast and there are other multicast capable GKs on the network, then alternate GKs are not used.

Use of dual (redundant) signaling links on the CA—There are two signaling links on each CA. During normal operation, one of these links on the active CA is active, and used for transporting H.323 (and other VoIP) signaling. The other link is standby. If the active signaling link goes down, the H.323 process restarts, and reestablishes communications over a good link (either of the signaling links on the CA). Typically, the link that comes up active is not the same link that originally went down. For additional details on setting up and using this capability, see the "Prerequisites for H.323 Networks" section and the "Link Failure Recovery Process" section.

Interoperability with Cisco CallManager and Other Endpoints

The interoperability between the Cisco BTS 10200 Softswitch, Cisco CallManager, and Cisco IOS H.323 GWs enhances the delivery of call control features between enterprise networks and service provider networks.

The Cisco BTS 10200 Softswitch can be used to connect calls between two phones that reside on different Cisco CallManager systems (see Figure 2). Signaling of certain information, for example connected name and number information, is transparently passed from the terminating
Cisco CallManager via the Cisco BTS 10200 Softswitch back to the originating Cisco CallManager.

Figure 2 Connection of Calls between Phones on Separate Cisco CallManager Systems

The following details are covered in this section:

Prerequisites for Interoperability

Limitations on Interoperability

Prerequisites for Interoperability

To ensure that the Cisco BTS 10200 Softswitch, the Cisco CallManager, and IOS-based H.323 GWs interoperate properly, ensure that your system meets the following conditions:

Verify that you are using the software releases that have been tested for interoperability with the features described in this document:

Cisco BTS 10200 Softswitch—Release 4.5.x

Cisco CallManager—4.0(3)

Cisco H.323 GWs, such as Cisco 2600 and Cisco 5400—IOS Release 12.3(7)T6


Note For a complete list of hardware and software items that have been tested for interoperability with the Cisco BTS 10200 Softswitch, see the Cisco BTS 10200 Softswitch Release Notes.



Note Contact your Cisco account team regarding any possible updates to these releases or patches that could occur after publication of this document.


On Cisco CallManager, configure the route to the Cisco BTS 10200 Softswitch as "intercluster trunk" with media termination point (MTP) selected on this trunk.


Note Some subscriber features can be provided by both the Cisco BTS 10200 Softswitch and Cisco CallManager. You must select MTP on Cisco CallManager so that Cisco CallManager can provide these subscriber features.


To ensure signaling compatibility between the Cisco BTS 10200 Softswitch and Cisco CallManager, perform the following provisioning operations on the Cisco BTS 10200 Softswitch. These procedure are provided in the "Provision for Interoperability with Cisco CallManager" section.

(Optional) Assign a main subscriber ID to the H.323 trunk group (TG) that connects the Cisco BTS 10200 Softswitch with Cisco CallManager. (This is similar to provisioning a TG to a PBX.)


Note Assign a main subscriber ID only if Cisco CallManager is used as a PBX. The system uses the subscriber ID to perform screening and routing.

If Cisco CallManager is not used as a PBX, do not assign a main subscriber ID, and the system uses the TG properties to perform screening and routing.


Enable quality of service (QoS) codecs, pulse code modulation mu law (PCMU) and pulse code modulation A law (PCMA), on any TG that is used for connection to Cisco CallManager. In addition, disable codec negotiation for the applicable H.323 TG profile. (Do not perform dynamic codec negotiation for these calls.)

Disable generic transparency descriptor (GTD) signaling on the Cisco BTS 10200 Softswitch for any trunk group TG used for connection to Cisco CallManager.

Verify that the value of the CODEC-MOD-DURING-CALL token in the CA-CONFIG table is set to its default value of Y.


Caution CODEC-MOD-DURING-CALL must be set to Y. If you set it to N, some features might not work.

Limitations on Interoperability

This section describes limitations on interoperability between the Cisco BTS 10200 Softswitch and Cisco CallManager.

Signaling and Processing Limitations

Signaling and processing limitations are as follows:

DTMF signaling limitation—Only the out-of-band DTMF mode is used over H.323 for signaling between Cisco CallManager and the Cisco BTS 10200 Softswitch.

Limitation on H.323-based calls on failover:

The Cisco BTS 10200 Softswitch uses Annex E redundancy capabilities to preserve stable calls during a restart or failover. However, all stable calls between the Cisco BTS 10200 Softswitch and Cisco CallManager are dropped during a restart or failover in the Cisco BTS 10200 Softswitch. Normal processing of new calls between the Cisco BTS 10200 Softswitch and Cisco CallManager resumes after the H.323 call processing function is running.


Note Annex E refers to ITU-T Recommendation H.323 - Annex E (05/99).



Note Failover refers to the following process—If an H.323-based call processing function in the Cisco BTS 10200 Softswitch experiences a fault, it can restart automatically and begin processing new calls. If it is unable to restart automatically, the standby process in the companion host machine becomes active and takes over the H.323 functions. This event (standby process taking over for a previously active process on a companion host) is called failover.


T.38 Fax calls cannot be connected between the Cisco BTS 10200 Softswitch and
Cisco CallManager.

Limitations on Subscriber Features

The Cisco BTS 10200 Softswitch provides connectivity with H.323 IOS-based GWs, Cisco CallManager, and MGCP-based GWs. These systems interoperate to provide subscriber features such as call forwarding, call waiting, call transfer, and three-way calling. See the "Interoperability Data for Cisco IOS, Cisco CallManager, and MGCP" section for additional data regarding interoperability of the Cisco BTS 10200 Softswitch with H.323 IOS-based gateways, Cisco CallManager, and MGCP-based gateways.

Annex E UDP Functionality

This section describes how the Cisco BTS 10200 Softswitch supports the User Datagram Protocol (UDP)-based Annex E feature of ITU-T Recommendation H.323 v4.


Note Annex E as used in this document refers to material that was previously in Annex E of Recommendation H.323, but is incorporated into the main body of Recommendation H.323 as of v4.

Throughout this document, Annex E refers to UDP-based Annex E functionality. (The Cisco BTS 10200 Softswitch does not implement TCP-based Annex E.) In this document, TCP refers to TCP-based signaling without Annex E functionality.


Restart and Failover Scenarios

Annex E implementation allows H.323 signaling to be transported between the Cisco BTS 10200 Softswitch and the far-end H.323 endpoint using UDP (connectionless) signaling instead of TCP (connection-oriented) signaling. The choice of UDP or TCP signaling is important in a Cisco BTS 10200 Softswitch H.323 process restart or CA failover scenario.


Note H.323 process restart means the H.323 GW instance in the Cisco BTS 10200 Softswitch restarts automatically.

CA failover means an automatic CA switchover, in which the standby CA side becomes active and takes over for the previously active CA side. To support the stability of active calls, the CA preserves call processing data, and replicates this data from the active CA side to the standby CA side on a regular basis.


If an H.323 restart or CA failover occurs, a remote H.323 endpoint using TCP signaling cannot reestablish the connection with the previously active process or CA. Therefore, the stable H.323 call(s) on that connection are cleared. However, a remote H.323 endpoint using UDP to communicate with the Cisco BTS 10200 Softswitch in a connectionless session can continue to communicate with the newly active process or CA side using the same connectionless session. This allows the remote endpoint to preserve and support the active call. The Annex E feature must be enabled on the Cisco BTS 10200 Softswitch, the H.323 GK, and the remote H.323 endpoint.


Note An H.323 call is considered to be stable, or in stable state, after the Connect message has been sent (or received) to (or from) the remote H.323 endpoint, and the media channels in both directions have been established. This definition differs somewhat from the typical telephony definition of a stable call.


Use of the Annex E feature is optional and configurable in the Cisco BTS 10200 Softswitch. Each H.323 trunk group (TG) in the Cisco BTS 10200 Softswitch can be independently provisioned to support either Annex E UDP-based signaling or non-Annex-E TCP-based signaling. Each logical H.323 GW instance in the Cisco BTS 10200 Softswitch can have multiple outgoing TGs, with each TG independently configured for Annex E UDP signaling or non-Annex-E TCP signaling.

Limitations on Annex E Support

Annex E must be supported and enabled on both the originating and terminating sides of a call leg for the Annex E redundancy to be supported. If the far-end H.323 device does not support Annex E UDP (or if Annex E is disabled), the following limitations apply:

For a RAS-based call (RAS parameter set to Y in the H323-TG-PROFILE or H323-TERM-PROFILE table), the Cisco BTS 10200 Softswitch automatically uses TCP mode (to match the far-end device), even if Annex E UDP mode is provisioned on the Cisco BTS 10200 Softswitch.


Note RAS (Registration, Admission, and Status) protocol is defined in ITU-T Recommendation H.225. It is used to communicate between H.323 GWs, endpoints, and GKs.


For a non-RAS call (RAS parameter set to N in the H323-TG-PROFILE or H323-TERM-PROFILE table), and with the ANNEXE-SUPP parameter set to Y in both the H323-GW table and the H323-TG-PROFILE or H323-TERM-PROFILE table, the Cisco BTS 10200 Softswitch uses Annex E UDP for outgoing calls. However, if the far end does not support Annex E, these calls fail.

Following are additional limitations on Annex E support:

All TCP-based calls are automatically cleared if the Cisco BTS 10200 Softswitch H.323 process restarts or if the CA fails over.

If Annex E is enabled but H.245 tunnelling is disabled, stable calls are dropped.

If the H.323-GW process in the Cisco BTS 10200 Softswitch restarts, or if the CA fails over to the other side, Annex E UDP-based transient calls (calls that are in the process of being set up) can be impacted as follows:

Typically, the system cannot complete the call setup, and the call is torn down.

Even with the call torn down, the called party might continue to receive ringing, and the ringing continues even if the calling party goes on-hook. Any of the following actions terminates the ringing on the handset of the called party:

The called party goes off-hook and then on-hook.

The Cisco BTS 10200 Softswitch signals the remote endpoint (the called party) that it should abandon the call after a specified amount of time has elapsed without successful call setup, and that time elapses.

The specific endpoint has a timer for incoming call setup, and that time elapses with no call setup.

After the ringing has terminated, the called party can receive a new incoming call or can go off-hook to receive dial tone.

Even with the call torn down, the calling party might continue to receive ringback tone, and the ringback tone continues until the calling party goes on-hook. Any of the following actions terminates the ringback tone on the handset of the calling party:

The calling party goes on-hook.

The calling party endpoint or phone is configured to abandon the call after a specified time without successful call setup, and that time elapses.

After the ringback tone has terminated, the calling party can receive a new incoming call or can go off-hook to receive dial tone.

Message Tunneling and Protocol Transparency for H.323-Based Transit Traffic

The Cisco BTS 10200 Softswitch supports the interconnection of multiple H.323-based devices by transparently passing certain H.323 messages in calls that transit the Cisco BTS 10200 Softswitch. It also provides signaling functions that enable interoperability with a variety of H.323 and non-H.323 endpoints. These functions are collectively referred to as H.323 protocol transparency functions in this document, and are described below:

Tunneling of QSIG messages inside H.225 per H.323v4 Annex M1—The Cisco BTS 10200 Softswitch can receive QSIG messages tunneled inside the H.225 call signaling messages on incoming H.323-based calls, and forward the QSIG messages on the outgoing H.323 call leg. The Cisco BTS 10200 Softswitch does not open or process this tunneled data, it simply forwards it to the next H.323 endpoint. No service provider provisioning steps are required for this function.


Note QSIG messages include, for example, Setup, Alerting, Connect, and Release Complete. Some QSIG messages, such as Call Proceeding, Facility, Information, Notify, and so forth, are mapped to the H.225 Facility message, as described in Annex M1.


Call-connect mode transparency—This feature refers to the two procedures for H.323 call connection, fast-start and slow-start. Each TG profile (or terminal profile) can be provisioned to operate in slow-start mode, fast-start mode, or auto mode. Each call leg will use the connection mode provisioned for the applicable TG profile or terminal profile. In addition, the system takes the following action based on this provisioning:

If the incoming call leg is provisioned for fast-start and the outgoing leg is provisioned for slow-start, the call can go through.

If the incoming leg is provisioned for slow-start and the outgoing leg is provisioned for fast-start, the call does not go through.

In auto mode, the system automatically uses the same call-connection mode on both legs of an H.323 transit call.

There are additional limitations on the system actions for fast-start and slow-start legs. Contact Cisco TAC if you need additional information on these limitations.

Call-proceeding message transparency—The system can send a call-proceeding message from the terminating endpoint to the originating endpoint as soon as it receives enough called-party digits to route the call. The system provides provisionable options that control the sending of the call-proceeding messages for H.323-based calls.

Preferential codec order transparency—On an incoming call leg using the fast-start connection method, the fast-start elements are contained in the SETUP message. For a leg using slow-start, the codec preferences come in the terminal capability set (TCS). The system transparently forwards this information to the remote endpoint on the outbound leg. This supports codec negotiation by the two endpoints. No service provider provisioning steps are required for this function.

Transparency of H.245 tunneling mode—The system receives H.245 messages that are tunneled inside H.225 messages on the incoming leg, and forwards the H.245 messages tunneled inside H.225 messages on the outgoing leg. This supports call processing functions between the originating and terminating endpoints, including scenarios in which one endpoint is H.323-based and the other is MGCP-based. The system provides provisionable options for H.245 tunneling. For H.323 transit calls, a provisionable option allows the system to consider what the peer leg is using as its tunneling mode.

H.245 message transparency—For H.323-to-H.323 calls, the system can pass H.245 messages, including, for example, EndSession and OpenLogicalChannelAck messages, from the incoming call leg to the outgoing call leg. It can also pass any nonstandard information elements received in the H.245 messages. No service provider provisioning steps are required for this function.

Transparency of Flash button (hook switch) functionality—When a call is in process and a user presses the Flash button or the hook switch on the handset, a hook-flash signal is sent to the Cisco BTS 10200 Softswitch in an H.245 message. The Cisco BTS 10200 Softswitch reacts by sending a hook-flash signal over H.245 to the other endpoint in the call. No service provider provisioning steps are required for this function.

DTMF relay method transparency—For H.323 transit calls, the Cisco BTS 10200 Softswitch transparently forwards the types of DTMF parameters listed below. (For this transparent passing functionality, no service provider provisioning steps are necessary.)

In-band

RTP payload (per IETF RFC 2833, RTP Payload for DTMF Digits, Telephony Tones and Telephony Signals)

Out-of-band (alphanumeric and signal)

Reattempt, Route Advance, and Hairpinning (Redirection)

The Cisco BTS 10200 Softswitch supports reattempt, route advance, and hairpinning (redirection). In H.323-based networks, the system supports these functions only for calls that use fast-start procedures on the H.323-based call leg(s). It does not support these features for calls that use slow-start procedures.


Note By default, the system attempts to send the FastStart element in the CALLPROCEEDING message. This could cause reattempt, route advance, or hairpinning to fail for H.323-to-H.323 (transit) calls. To control the sending of FastStart in CALLPROCEEDING, see the "Reattempt, Route Advance, and Hairpinning (Redirection)" section.


Reattempt and Route Advance on H.323-Based Calls

If a call does not complete, the Cisco BTS 10200 Softswitch can reattempt the call based on the release cause code. The action for each received cause code is provisionable in the Cause Code Map (cause-code-map) table. The call can be reattempted to the same TG or to another TG. The selection of the next TG depends on the cause code mapping analysis and on carrier-dependent routing rules.

Table 1 shows an example of mapping cause codes to actions for H.323 TGs.

Table 1 Example of Cause Code Mapping for H.323 TGs 

Received Cause Code
Standard Cause Code
Action
Cause Code Description
Action Description

001

001

REATTEMPT

Unassigned number

Reattempt the call by requerying the GK.

003

003

REATTEMPT

No route to the destination

Reattempt the call by requerying the GK.

021

021

REATTEMPT

Call rejected

Reattempt the call by requerying the GK.

031

031

REATTEMPT

Normal, unspecified

Reattempt the call by requerying the GK.

034

034

REATTEMPT

No circuit available

Reattempt the call by requerying the GK.

038

038

REATTEMPT

Network is out of order

Reattempt the call by requerying the GK.

041

041

REATTEMPT

Temporary failure

Reattempt the call by requerying the GK.

042

042

REATTEMPT

Switch is congested

Reattempt the call by requerying the GK.

047

034

ROUTE-ADVANCE

Resource unavailable, unspecified

If additional routes are available in the route table, route advance to the next TG within the route.

049

049

REATTEMPT

QoS is not available

Reattempt the call by requerying the GK.

063

063

REATTEMPT

Service or option
not available

Reattempt the call by requerying the GK.


The specific action for route advance is based on provisioning of the route table in the Cisco BTS 10200 Softswitch database. The service provider uses the route table to provision a list of up to 10 trunk groups (TG1 to TG10), and a parameter for selecting the priority of the TGs for routing (TG-SELECTION). The individual TGs can be H.323-based, or can be based on any of the other supported protocols. The system attempts to route the call on the highest priority TG. If the call cannot be completed on the highest priority TG, the system attempts to use the next (lower priority) TG, a process known as route advance. The system attempts route advance to lower priority TGs up to five times. (Any TG in the list that is administratively out of service is not counted as an attempt.) If all five attempts fail, the call is released, and the system provides a release announcement.

Hairpinning (Call Redirection) on H.323-Based Calls

On an incoming PSTN call, if the GK cannot route the incoming call, or if the GK determines that the call termination is on PSTN, the Cisco BTS 10200 Softswitch can send the call back out to the PSTN (hairpinning) or to another H.323 call leg (redirection).

T.38 Fax Support over H.323

This section describes T.38 fax support over H.323.

Supported Interfaces and Interworking

The Cisco BTS 10200 Softswitch supports ITU-T T.38 procedures on the following H.323 interfaces:

H.323 trunk using fast connect procedure (fast start)

H.323 trunk using non-fast connect procedure (slow start)

H.323 trunk using GK (H.225 RAS messaging)

H.323 trunk not using GK (direct trunks)

H.323 trunk with and without H.245 tunneling enabled


Note The system does not support T.38 procedures for H.323 subscribers.


The Cisco BTS 10200 Softswitch supports interworking of T.38 procedures between H.323 trunks and the following interfaces:

NCS MTA subscribers

MGCP subscribers

MGCP (or TGCP) trunking gateways (SS7, ISDN)

SIP trunks

T.38 Fax Call Features

The following call features apply to T.38 fax calls:

For the H.323 interface, the system uses H.323 Annex D v2 to handle the fax over T.38.

For H.323 calls, if the non-H.323 endpoint fails to switch to T.38 fax while the H.323 side is already switched to T.38 fax, the H.323 side reapplies H.245 procedure to return to audio codec.

After a fax is done, the call falls back to a voice call.


Note T.38 fax calls cannot be connected between the Cisco BTS 10200 Softswitch and
Cisco CallManager.


T.38 Glare Handling

The Cisco BTS 10200 applies a call agent controlled switch to T.38 Fax media when initiated by either the originating or terminating endpoint. This includes when both endpoints initiate the switch, causing a glare condition at the Cisco BTS 10200.

For details about glare handling, contact your Cisco support representative.

End-to-End SDP Exchange for T.38 Media and the H.323 Interface


Note This section does not apply to T.38 fax transmissions across H.323-to-H.323 calls on the Cisco BTS 10200 Softswitch. In this case, the H.245 messages are exchanged directly through the Cisco BTS 10200 Softswitch.


The H.323 protocol must negotiate T.38 fax connection attributes (example: bit rate, maximum buffer size) during the voice call establishment using Terminal Capability Set (TCS) messages. However, for SIP and MGCP, the endpoint does not report T.38 fax connection attributes until the fax actually starts. When this occurs between an interworking H.323 endpoints to SIP/MGCP endpoints, and the H.323 endpoint is ready to send TCS message during voice call establishment phase, the T.38 fax attributes are not available from MGCP/SIP endpoints.

To overcome this interworking limitation, all Cisco IOS gateways assume the defaults for these attributes while exchanging TCS messages. Cisco BTS 10200 follows the same philosophy for H.323 to/from MGCP/NCS and H.323 to/from SIP calls. Cisco BTS 10200 assumes following defaults:

Maximum Bit Rate = 14.4 kbps (This field can be configured in T38_MAX_BIT_RATE field in the CA_CONFIG table)

Fill Bit Removal = false

MMR Transcoding = false

JBIG Transcoding = false

Data Rate Management Method = transferredTCF

Maximum Buffer Size = 200 (This field can be configured in T38_MAX_BUFFER_SIZE field in CA_CONFIG table)

Maximum Datagram Size = 72 (This field can be configured in T38_MAX_DATAGRAM_SIZE field in the CA_CONFIG table)

Error Correction = t38UDPRedundancy

To overcome other interworking limitations with SIP, IOS H.323 gateways send the fax UDP port in H.245 Open Logical Channel (OLC) messages. A provisioning field (REMOTE_FAX_PORT_ RETRIEVAL_MSG) is added in h323-tg-profile and h323-term-profile, enabling the H.323 interface to read the remote endpoint fax UDP port either from OLC message or from OLC Ack message.

Provisionable Parameters for T.38 Fax Over H.323

For details on provisioning parameters, see the "H.323-Based T.38 Fax Parameters" section.

Additional H.323-Related Features

The Cisco BTS 10200 Softswitch provides the following additional provisionable H.323-based features:

DTMF relay support on MGCP-to-H.323 calls—For MGCP-to-H.323 (fast-connect) calls, RFC-2833 capabilities are advertised for the H.323 call leg based on static information configured for the H.323 TG. This is because the far-end H.323 endpoint capabilities (such as DTMF, Fax, and so forth) are not available when the MGCP leg has to complete the two-ended connection. Therefore, all far-end H.323 capabilities must be configured in either the outgoing (for outgoing H.323 calls) or incoming (for inbound H.323 calls) H323-TG-PROFILE (or H323-TERM-PROFILE) table.

Asymmetric codec resolution—Asymmetric codec refers to the use of different codecs for forward and reverse logical channels created for a slow-start call. In most network scenarios, asymmetric codec is avoided by means of codec negotiation, and, if necessary, some additional resolution techniques when the call is set up. The Cisco BTS 10200 Softswitch resolves asymmetric codec based on a master/slave determination and a codec back-off algorithm.

Facility message—The FACILITY message is used primarily for passing tunneling and other special information. The service provider provisions a flag in the Cisco BTS 10200 Softswitch to indicate whether the far-end device supports receiving of the FACILITY message. If the far-end device flag indicates that it does not support the FACILITY message, the Cisco BTS 10200 Softswitch can open a separate H.245 TCP connection and use the PROGRESS message to send fast-start information elements backward in the direction of the call.

Media cut-through—The cut-through parameter can be used to trigger the originating far-end device to perform media cut-through. This is provisionable in the Cisco BTS 10200 Softswitch. In most cases the system handles media cut-through automatically (default behavior).

Empty capability set (ECS) message handling—When an endpoint in a call receives an ECS message, it reacts by closing its forward logical channel. The sending endpoint might also close its forward logical channel. When the Cisco BTS 10200 Softswitch is the sending endpoint it closes the channel (or not) based on the values provisioned for the ECS method. If provisioned for automatic ECS mode (default), the system acts as follows:

For call legs connecting to Cisco CallManager, the Cisco BTS 10200 Softswitch closes its own forward logical channel.

For all other types of H.323 devices, the Cisco BTS 10200 Softswitch does not close its own forward logical channel.

Configurable status enquiry timer—If a Call Agent failover occurs, the Cisco BTS 10200 Softswitch uses Annex E UDP transport to send a STATUS ENQ message to all calls that were previously stable or transient, and starts the STATUS ENQ timer per call. This timer is stopped gracefully when a STATUS message is received from the far end. After timeout, the Cisco BTS 10200 Softswitch releases the corresponding call.

Overload Control—Overload control for the H.323 protocol on the BTS is just one aspect of the operation of the Overload Control feature on the entire softswitch. The overload control feature detects and controls machine overload due to traffic congestion from H.323 networks.

The BTS 10200 performs Overload Control with regard to H.323 networks as follows:

The BTS10200 reports the machine congestion level (MCL) to the H.323 network by sending the Resource Availability Indicator (RAI) message to the Gatekeeper.

The BTS 10200 reports CallCapacity data in all Admission Request (ARQ), Disconnect Request (DRQ) and ReleaseComplete messages.

If alternate endpoints are configured, the BTS 10200 reports them in the Registration Request (RRQ) message to the Gatekeeper.

When an overload condition exists, the BTS 10200 rejects incoming calls from the H.323 network (when required by the MCL level action) by responding to the incoming SETUP with a RELEASE-COMPLETE with cause=42—switching equipment congested.

When a peer gateway indicates congestion, the BTS 10200 does not route outgoing calls using the particular trunk group for a period of time.

The tokens SEND-RAI, ALT-ENDPOINT1, ALT-ENDPOINT2, ALT-ENDPOINT3, ALT-ENDPOINT4, and ALT-ENDPOINT5, are added to the H323-GW Table to support Overload Control.

A new token, PEER-GW-OVERLOAD-TIMER, is added to the H323-TG-PROFILE Table to indicate that a trunk group is congested. When this timer is started, traffic will not be routed to the trunk group. When the timer expires, traffic will resume to the trunk group.


Note The configurable parameters mentioned above are not be entered by a user through CLI provisioning. These parameters are contained in one of the system configuration files.


Planning

This section provides guidelines and procedures for planning your H.323-based systems. It includes the following sections:

Planning for Redundant Operation of H.323 Links

Prerequisites for H.323 Networks

Restrictions and Limitations


Tip Prerequisites are tasks or conditions (outside the immediate scope of this document) that are required before these new Cisco BTS 10200 Softswitch features can work as specified.

Restrictions and limitations are special conditions or scenarios for which these features might not work, or might behave in an unexpected manner.


Planning for Redundant Operation of H.323 Links

Figure 3 shows an H.323 network with the Cisco BTS 10200 Softswitch, H.323 GW (with Cisco IOS), and a gatekeeper (GK). Refer to this figure as needed during the planning procedures described in this section. During startup, the Cisco BTS 10200 Softswitch registers its active IP address (the address used for H.323 signaling) with the GK. The peer H.323 GW dynamically obtains the IP address by sending a query to the GK. When the GW signals the Cisco BTS 10200 Softswitch, it transmits to this IP address.

Figure 3 H.323 Network with Gatekeeper Present

The internal interfaces of the Cisco BTS 10200 Softswitch are shown in Figure 4. There are two signaling links on each CA (shown in the drawing as IF1 and IF2 on each CA unit).

One link connects IF1 on the CA to a port on Catalyst Switch A, and is in VLAN-2A.

The other link connects IF2 on the CA to a port on Catalyst Switch B and is in VLAN-2B.

Figure 4 Cisco BTS 10200 Softswitch Network Configuration


Note The same IP address is used for IF1 on both the active and standby sides of the CA, and likewise the same IP address is used for IF2 on both the active and standby sides.


Prerequisites for H.323 Networks

This section lists prerequisites for video phones, and for networks with and without GKs.

Video Phones

It might not be necessary to configure the GK address in the individual H.323 video phones. The Cisco BTS 10200 Softswitch can receive incoming calls from an H.323 phone with or without using the GK, provided that the H.323 phone supports direct routing. The H.323-based video phones must have the following capabilities:

The video phones must be able to communicate with the GK, if a GK is present in the network.

The video phones must be capable of using slow-start connection procedures.

Networks with GKs

If the Cisco BTS 10200 Softswitch is connected to one or more GKs in the H.323 network, the GKs must be configured to support video calls:

The GKs can be configured to reroute an originating call from a video terminal to the Cisco BTS 10200 Softswitch first (before completing the call to the terminating video terminal). The Cisco BTS 10200 Softswitch participates in the video call as an H.323 proxy (IP-to-IP MGW).

The GKs can be configured to provide validation and registration of the video phone functions performed by the Cisco BTS 10200 Softswitch. The Cisco BTS 10200 Softswitch does not provide GK functions such as registration and authentication of endpoints.

Networks Without GKs (Direct Routing)

Setting Up Direct Routing on the Cisco BTS 10200 Softswitch

For direct routing scenarios (not using RAS signaling to a GK) the transport service access point (TSAP) addresses of the far-end H.323 endpoints must be identified, so that they can be provisioned in the Cisco BTS 10200 Softswitch database. The TSAP addresses are provisioned for each applicable TG or terminal.

Setting Up Direct Routing on the Peer H.323 GW

If a GK is not used, direct routing must be set up on each of the peer H.323 GWs that communicates with the Cisco BTS 10200 Softswitch. Use this procedure to set up direct routing. While performing this procedure, refer to Figure 4 for a description of signaling interfaces and parameters.

Obtain information from the Cisco BTS 10200 Softswitch and provision the H.323 GW in the following way:


Step 1 On the UNIX level on the active CA, enter the following command (example shown) to determine the IP addresses of the signaling interfaces (IF1 and IF2).

host# nslookup h3a-SYS37CA146.ipclab.cisco.com

Typical system response:
Server: lion.ipclab.cisco.com 
Address: 10.89.224.1 
Name: h3a-SYS37CA146.ipclab.cisco.com 
Addresses: 10.89.226.17, 10.89.225.17

Tip The domain name for this H.323 link always includes h3a-SYS. The full domain name is shown in the Network Information Data Sheet (NIDS) that was supplied with your system. Alternatively, you can search in the DNS server for domain names containing h3a-SYS.


Step 2 On the Cisco BTS 10200 Softswitch, enter the following CLI command (example shown) to determine which signaling interface (IF1 or IF2) is active on the active CA. The active signaling interface carries the H.323 signaling (and other protocol signaling, if present). The system response contains an IP address for the currently active signaling link.

status h323-gw id=GW37_Central_4;

A typical system response is shown below.


Note The IP ADDRESS displayed in this system response is the active IP address.


status h323-gw id=TB37_Central_4;

ADMIN STATE -> ADMIN_INS 
H3A PROCESS NUMBER -> 40
H3A PROCESS NAME -> H3A4
ENDPOINT ID -> 6333EC4400000005
ACTIVE CALLS -> 0
RAS STATE -> CCH323_RAS_STATE_IDLE
RAS PORT -> 57781
IP ADDRESS -> 10.89.225.17
REGISTERED GATEKEEPER ID -> H5-GK
PRIMARY GATEKEEPER ID -> H5-GK
PRIMARY GATEKEEPER PORT -> 1719
PRIMARY GATEKEEPER IP -> 10.89.227.80
H323 VERSION -> 4
TIME TO LIVE -> 60
NUM ALT GATEKEEPERS -> 0
ALT GATEKEEPER PERMANENT -> TRUE
THRESHOLD ENABLED -> FALSE
OUT OF RESOURCES -> FALSE
ALT GATEKEEPER LIST -> 

Step 3 On the peer H.323 GW, set up two IP addresses. Set the IP address that is currently active on the CA as primary, and set one alternate IP address (to be used if the primary IP address becomes unreachable).


Tip The active IP address is the address returned in the status query (Step 2), and the standby IP address is the other IP address listed in the response to the nslookup query (Step 1).


a. If the peer H.323 GW is IOS-based, configure this using two dial-peer entries with preferences. Set the preference to 1 on the dial-peer that has the session-target IP address for the active signaling link of the CA. Set preference to 2 on the dial-peer that has the session-target IP address for the standby signaling link of the CA.

b. If the peer H.323 GW is a Cisco CallManager H.323 intercluster trunk, configure this in the Remote Cisco CallManager Information dialog box as Server IP Address 1 and Server IP Address 2.

Step 4 On the peer H.323 GW, set the H.225 TCP timeout delay to 3 seconds. The purpose of reducing this to 3 seconds is to allow the GW to switch promptly to a secondary IP address if the primary (top preference) IP address goes down.


Note It is important to set the timeout delay in the peer H.323 GW, because the default timeout delay can be much greater than three seconds, which can cause unacceptable call setup delays if one signaling link on the CA goes down.


Step 5 Verify that the active connection is functioning properly by completing several test calls.


Restrictions and Limitations

This section describes restrictions and limitations applicable to the H.323 implementation.

Interoperability with Other H.323 Endpoints

The features described in this document are based on ITU-T Recommendation H.323, Packet-based multimedia communications systems, Draft v4 (11/2000). H.323-based endpoints that do not comply fully with this draft of the ITU-T recommendation might not support all of these same features. When you are selecting H.323-based devices, we recommend that you discuss your specific requirements with your Cisco account team.

The Cisco BTS 10200 Softswitch Release Notes document identifies the specific peripheral platforms and software loads that have been tested by Cisco for H.323 interoperability with the Cisco BTS 10200 Softswitch software. If you would like to use additional features and devices, ask your Cisco account team for assistance.


Note The interoperability list in the Cisco BTS 10200 Softswitch Release Notes includes H.323-based video phones, analog telephone adapters (ATAs), H.323-based PRI gateways, H.323 IP-to-IP GWs, H.323 GKs, and Cisco CallManager.


Functionality Related to Video Phones

The Cisco BTS 10200 Softswitch supports basic call functions for video phones, along with the following subscriber features:

Call forwarding unconditional (CFU) and call forwarding busy (CFB)

Calling identity features including presentation and blocking

The following restrictions and limitations apply to video phone calls connected through the Cisco BTS 10200 Softswitch:

Video calls must be originated using slow-start procedures. H.323 fast-connect signaling does not work for video calls.

If a video phone uses an H.245 tunneling feature, H.245 tunneling must be disabled in the Cisco BTS 10200 Softswitch H323-TERM-PROFILE table associated with that phone.

In some cases, video phones do not support codec negotiation. When codec negotiation is not supported by the phones, the originating and terminating video phones must use the same codec.

Video calls cannot be originated or terminated using multiline hunt group (MLHG) line access.

In general, the Cisco BTS 10200 Softswitch preserves stable calls during an internal transient such as a process restart or platform switchover. However, H.323-based calls can be preserved only if the connection uses both H.323 Annex E and fast-start functionalities or H.323 Annex E and slow-start with H245 Tunneling enabled. If the video endpoints in a call do not support fast-start or slow-start with H245 Tunneling enabled, these calls are dropped when there is a platform switchover or a process restart that affects H.323 call processing.

Functionality Related to ATA Clients

The Cisco BTS 10200 Softswitch supports basic call functions for ATA clients using H.323 protocol, along with the following subscriber features:

CFU, CFB, and call forwarding no answer (CFNA)

Call waiting (CW) and calling ID delivery on call waiting (CIDCW)

Calling identity features including presentation and blocking

Call transfer (CT) and three-way calling (TWC)

Interoperability Data for Cisco IOS GWs, Cisco CallManager, and MGCP GWs

The Cisco BTS 10200 Softswitch provides connectivity with H.323 IOS-based gateways, Cisco CallManager, and MGCP-based gateways. These systems interoperate to provide subscriber features such as call forwarding, call waiting, call transfer, and three-way calling. See the "Interoperability Data for Cisco IOS, Cisco CallManager, and MGCP" section for additional interoperability data.

Installing

There are no H.323-specific requirements for installation procedures for the Cisco BTS 10200 Softswitch as a result of the features covered in this document. (Installation procedures include hardware installation, cabling, jumpstart, application installation, software upgrade, and hardware upgrade.)

Configuring

This section explains how to perform the following tasks:

Provision H.323-Based TGs, Logical GWs, and GKs

Provision H.323-Based Video Phone Terminals and Subscribers

Provision H.323-Based Outbound Routing Data

Provision H.323-Based Inbound Routing

Provision ANI Screening and Routing

Provision for Interoperability with Cisco CallManager

Provision Annex E Functionality

Provision Additional H.323 Options

To see a complete set of commands, see the "Example of Provisioning Script" section.


Note The tasks described in this section include examples of CLI commands that illustrate how to provision specific features. Most of the database tables in the Cisco BTS 10200 Softswitch have additional tokens that are not used in these examples. For a complete list of all CLI tables and tokens, refer to the Cisco BTS 10200 Softswitch Command Line Interface Reference Guide.



Note The command sequences shown in this section provide guidance on how to provision a new system. Therefore, in most cases the commands are "add" commands. If you are modifying previously-provisioned GWs, TGs, and so forth, use the "change" commands.


Provision H.323-Based TGs, Logical GWs, and GKs

The commands in this section provision the following entities on the Cisco BTS 10200 Softswitch:

H.323-based TGs.

H.323-based logical GWs internal to the Cisco BTS 10200 Softswitch (the Cisco BTS 10200 Softswitch provides a maximum of four H.323-based GWs).

Connections to an H.323 GK, if GKs are present in the network.

H.323-Based Logical GWs Internal to the Cisco BTS 10200 Softswitch

Each of the H.323-based internal GWs supports trunks, lines, routing options, and communications with external H.323 endpoints. Each GW can communicate with a GK, if one is present in the network. The parameters described in this section support these functions.

Prerequisites

The Cisco BTS 10200 Softswitch database should already be populated with basic provisioning options as described in the Cisco BTS 10200 Softswitch Provisioning Guide.

SUMMARY STEPS

1. ADD H323-TG-PROFILE

2. ADD TRUNK-GRP

3. ADD QOS

4. ADD H323-GW

5. ADD H323-GW2GK

6. CHANGE TRUNK-GRP


Note We recommend that you assign a specific type of inbound routing to each of the four H.323 GWs according to your network requirements. For example, assign tsap-addr routing on one GW, gw-id routing on one GW, "none" on one GW, and choose the routing type for the fourth GW according to your network design. Selecting "none" results in the most efficient processing, but it reduces flexibility.


DETAILED STEPS