The Cisco® High-Density Packet Voice Digital Signal Processor (DSP) Module (PVDM2) enables Cisco Integrated Services Routers to provide high-density voice connectivity, conferencing, and transcoding capabilities in Cisco IP Communications solutions. Cisco Integrated Services Routers provide enterprises and service providers with a toll bypass solution by connecting their existing telephony equipment (such as private branch exchanges [PBXs], key systems, analog telephones, and fax machines) to a toll-free data network and eventually migrating customers to Cisco AVVID Architecture for Voice, Video and Integrated Data IP telephony solutions.
The high-density packet voice DSP modules are available in five versions: PVDM2-8, PVDM2-16, PVDM2-32, PVDM2-48, and PVDM2-64 (Figure 1). Tables 1 and 2 show the number of voice channels and codecs that each PVDM2 module supports.
Figure 1. PVDM2 Top and Bottom Views
Top
Bottom
PVDM2-64
PVDM2-48
PVDM2-32
PVDM2-8 and PVDM2-16
Table 1. Channel Density of Each PVDM2 Module
Name
Description*
Number of DSPs
Maximum Number of Channels in G.711
Maximum Number of Channels in High-Complexity Codecs
Maximum Number of Channels in Medium-Complexity Codecs
PVDM2-8
8-channel packet fax and voice DSP module
1**
8
4
4
PVDM2-16
16-channel packet fax and voice DSP module
1***
16
6
8
PVDM2-32
32-channel packet fax and voice DSP module
2
32
12
16
PVDM2-48
48-channel packet fax and voice DSP module
3
48
18
24
PVDM2-64
64-channel packet fax and voice DSP module
4
64
24
32
* The number of channels in PVDM2 product numbers and descriptions is the maximum channel density with the G.711 codec.
** One Texas Instrument TNETV2505GGW DSP
*** One Texas Instrument TNETV2510GGW DSP
Table 2. Codec Support on the PVDM2 Module
Name
High-Complexity Codecs
Medium-Complexity Codecs
PVDM2 Module
G.723.1, G.728, G.729, G.729b, iLBC, and Modem Relay
G.7112, g.729a, G.729ab, G.726, G.722, and Fax Relay
* PVDM2 can support a higher density of G.711 calls than that of other medium-complexity codecs. See Table 1.
PVDM2 connects to the host through 80-pin single inline memory module (SIMM) slots. The module is field insertable and removable. Figure 2 shows how PVDM2 is plugged into PVDM2 SIMM slots on the Cisco high-density digital voice network modules.
Figure 2. PVDM2 SIMM Slots on the Cisco High-Density Digital Voice Network Modules
Features and Benefits
Investment Protection and Field-Upgradable Capability
PVDM2 is used across a series of Cisco Integrated Services Routers and high-density voice network modules, allowing users to distribute or reuse DSP resources among the routers or network modules as needed. The field-upgradable capability enables users to easily scale their voice deployments.
In addition, each DSP on the PVDM2 provides four times the processing power and more memory than the existing PVDM. The high performance of PVDM2 supports future growth.
High Density and Flexibility
PVDM2 provides high call density per DSP and flexibility of channel allocation. The maximized support of uncompressed G.711 voice calls optimizes DSP utilization for the solutions, mainly based on G.711 codecs such as IP telephony, in a LAN where the bandwidth consumed by uncompressed calls is not a concern.
Conferencing and Transcoding Services
With PVDM2, Cisco Integrated Services Routers and voice network modules provide both digital and analog voice connections and conferencing and transcoding services. Table 3 shows conferencing sessions support per DSP with CUCM (Cisco Unified Communications Manager). In conjunction with host software, PVDM2 supports universal transcoding when needed. Universal transcoding allows transcoding from any supported codec to any other supported codec. As a general rule, the number of sessions needed for a universal transcoding channel is the sum of the session requirements for two separate voice channels, one running each of the configured codecs. For example, a channel running universal transcoding from a G.729a codec to iLBC would need the session capacity for a voice channel running the G.729a codec and MIPS (million instructions per second) for a voice channel running the iLBC codec.
Table 3. Hardware Conferencing Support on PVDM2 with CUCM
Codec Type
Number of Conferences per DSP (PVDM2-16)
G.711
8 conferences X 8 conferees
G.729a
2 conferences X 8 conferees
Improved Voice Quality
PVDM2 performs compression, voice activity detection, jitter management, and echo cancellation functions to improve voice quality. The echo cancellation offered in PVDM2 has a tail length of 64 milliseconds (ms) and complies with International Telecommunication Union (ITU)-T G.168.
Availability of Features
Table 4 summarizes the availability of features.
Table 4. Features Availability
Name
Platform Support
Availability
Release
PVDM2-8, PVDM2-16, PVDM2-32, PVDM2-48, and PVDM2-64
NM-HDV2, NM-HDV2-1T1/E1, and NM-HDV2-2T1/E1
IP voice or IP plus above images
Cisco IOS® Software Release 12.3(7)T
PVDM2-8, PVDM2-16, PVDM2-32, PVDM2-48, and PVDM2-64
Cisco 2801*, 2811, 2821, and 2851 Integrated Services Routers
IP voice and above images
Cisco IOS Software Release 12.3(8)T4
PVDM2-8, PVDM2-16, PVDM2-32, PVDM2-48, and PVDM2-64
EVM-HD-8FXS/DID, EM-HDA-8FXS, and EM-4BRI-NT/TE
IP voice and above images
Cisco IOS Software Release 12.3(8)T4
PVDM2-8, PVDM2-16, PVDM2-32, PVDM2-48, and PVDM2-64
Cisco 3825 and 3845 Integrated Services Routers
IP voice and above images
Cisco IOS Software Release 12.3(11)T
* The conferencing and transcoding feature on the Cisco 2801 will be available in a future Cisco IOS Software release.
Product Specifications
Table 5 presents product specifications.
Table 5. Product Specifications
Feature
Specifications
Components
DSP
• Texas Instruments TNETV2510GGW for PVDM2-16, PVDM2-32, PVDM2-48, and PVDM2-64
• Texas Instruments TNETV2505GGW for PVDM2-8
DSP CPU Clock
• 200 MHz for TNETV2510GGW
• 175MHz for TNETV2505GGW
DSP External Memory
128-megabit synchronous dynamic RAM for each DSP (for both TI 2510 and TI 2505)
Interface
80-pin SIMM interface
Features
Echo Cancellation
Software echo cancellation compliant with ITU-I G.168, with 64-ms tail coverage
Approvals and Compliance
Safety
• IEC 60950 (worldwide) and AS/NZS 3260 (Australia and New Zealand)
• CAN/CSA-C22.2 No. 60950 (Canada) and GB4943-95 (People's Republic of China)
• EN60950 (CENELEC; includes EU and EFTA)
• SS337 (Singapore; PSB approval), NOM-019-SCFI-1998 (Mexico), and UL 60950 3rd edition (United States)
Cisco offers a wide range of support services to accelerate customer success. Innovative Cisco service programs are delivered through a unique combination of people, processes, tools, and partners, resulting in high levels of customer satisfaction. Cisco services help you protect your network investment, optimize network operations, and prepare the network for new applications to extend network intelligence and the power of your business. For more information about Cisco services, go to Cisco Technical Support Services or Cisco Advanced Services.