Cisco Cisco IOS Software Release 12.4(2)XB6

This section provides information about the following concept:

High-Density Packet Voice Feature Card Key Features, page 3

The High-Density Packet VFC features the following:

Port densities on the High-Density Packet Voice Feature Card depend on codec complexity:

Low complexity: up to 384 G.711, Clear-Channel, and Fax/Modem Passthrough ports 

Medium complexity: up to 192 G.726, G.729a, G.729ab, fax-relay ports

High complexity: up to 144 G.728, G.729, G.729b, G.723.1, Modem Relay, and GSMAMR-NB 
ports (AMR-NB supports a packetization period of 20 ms only)

Each High-Density Packet VFC can support the following:

Up to six AS5X-PVDM2-64s. 

Each AS5X-PVDM2-64 has four DSPs

Each DSP can support up to 16 low-complexity calls, 8 medium-complexity calls, or 6 
high-complexity calls.

The DSPs are always set to flex mode and the codec complexity is determined by the codec that is 
negotiated.

Support is provided for packetization periods for all codecs: 10 ms to 30 ms with configurable 
increments of the minimum defined by the codec or 5 ms, whichever is greater.

Support is provided for H.323, SIP, and MGCP call control protocols. 

DSPware is bundled into the Cisco IOS image, but the DSPware is also supported as a standalone 
firmware image that can be loaded to the DSP (independent of the Cisco AS5350XM and 
Cisco AS5400XM image).

High-Density Packet VFCs are hot-swappable and replaceable (using online insertion and removal 
[OIR]). However, you should complete the software procedure in the 

“Using Online Insertion and 

Removal to Replace the High-Density Packet Voice Feature Card” section on page 19

 before 

removing a card from the chassis.

The PVDM2 SIMM is field-replaceable.

G.168-compliant echo cancellation for tail circuits up to 128 ms can be configured by software.

Support is provided for voice activity detection (VAD), comfort noise generation, adaptive jitter 
buffering, and caller ID.

AMR-NB calls are brought up with the common modes from the mode-set of both endpoints.

Beginning with Cisco IOS Release 12.4(9)T, support is provided for the Media and Signaling 
Authentication and Encryption Feature for Cisco IOS H.323 Gateways, which provides 
authentication, integrity, and encryption of voice media and call control signaling for H.323 
protocol-based voice gateways. For more information about this feature and instructions for 
configuration, refer to