Configuring Codec Complexity
On platforms that support the C549 DSP technology, the codec complexity is configured on the voice card (for example, the 2600/3600/VG-200 High Density Voice Network Module). Some platforms support only high complexity because they have enough DSPs onboard to support all T1/E1 channels that use the high complexity mode. To specify call density and codec complexity according to the codec standard that is used, use the codec complexity command in voice-card configuration mode.
Consider Examples 2-1 and 2-2, which show the supported codec complexity modes for the C549 and C5510 DSPs, using context-sensitive help. Notice the C5510 DSPs support a flex complexity mode, which allows the DSPs to automatically switch into the optimal complexity mode for a given call, unlike the C549 DSPs, which require you to use the high complexity mode (which supports the fewest number of calls) if the DSPs ever need to run in high complexity mode.
Example 2-1 Configuring Codec Complexity on C549 DSPs
Example 2-2 Configuring Codec Complexity on C5510 DSPs
When you use flex complexity, up to 16 calls can be completed per DSP. The number of supported calls varies from 6 to 16 and is based on the codec used for a call. Also notice the secure option, which supports Secure RTP (SRTP). SRTP secures voice streams by providing authentication and encryption services to RTP.
The show voice dsp command, as demonstrated in Example 2-3, can be used to verify codec complexity configurations.
Example 2-3 Verifying Codec Complexity
DSP Requirements for Media Resources
The number of DSPs required is a key factor when deploying media resources using DSPs. This mainly depends on two factors: DSP type and the codec being used. In general, the old packet voice/data modules (PVDMs) support fewer sessions than the new packet voice DSP modules, generation 2 (PVDM2s), and G.711-only media resources require less resources than mixed-codec or G.729 resources.
Resource Allocation on the NM-HDV (C549-Based Hardware)
You configure each DSP individually, and each DSP functions independently of the others. The conferencing and transcoding MTP resources must be allocated to different DSPs, and a single DSP can support only one of these functions at a time. The configuration specifies which function each DSP will perform.
A High-Density Voice Network Module (NM-HDV) can be associated with only a single Cisco Unified Communications Manager.
Resource Allocation on the NM-HDV2, NM-HD-xx, and PVDM2 (C5510-Based Hardware)
Hardware resources based on the C5510 chipset are allocated using DSP profiles that define the resource type within the profile. Multiple profiles can be defined on a single gateway. These profiles can then be registered to different Cisco Unified Communications Manager clusters.
A PVDM2 is a module that can carry up to four C5510 DSPs. Table 2-9 lists the DSP per PVDM2 allocation.
Table 2-9 DSPs per PVDM2
|
PVDM2 |
Number of C5510 DSPs |
|
PVDM2-8 |
1/2 |
|
PVDM2-16 |
1 |
|
PVDM2-32 |
2 |
|
PVDM2-48 |
3 |
|
PVDM2-64 |
4 |
Note Both the PVDM2-8 and the PVDM2-16 have a single DSP. The DSP on the PVDM2-8 has one-half the capacity of the DSP used on other PVDM2 modules. A PVDM2-8 can be used for conferencing, but with lower performance numbers than the other DSPs.
Conferencing resources can either be G.711-only or mixed mode (that is, at least one party with G.729). Mixed-mode conferences require more DSP resources because the DSP will perform transcoding and mixing operations.
Note For PVDM and PVDM2-based conferencing, the maximum number of conference participants is independent from the maximum number of conferences. This means that whether a conference has three, five, or eight participants, it counts the same against the number of simultaneous conferences supported on a DSP.
Table 2-10 shows the various DSP resources for conferencing and their performance.
Table 2-10 Conferencing DSP Resources
|
|
Conferences |
||
|
Hardware Module or Chassis |
DSP Configuration |
All Participants Use G.711 (a-law, mu-law) |
One or More Participants Use G.729 or G.729a |
|
NM-HDV2 |
1 to 4 of: |
Conferences/PVDM2: |
Conferences/PVDM2: |
|
(8 participants |
PVDM2-8 (1/2 DSP) |
4 |
1 |
|
per conference) |
PVDM2-16 (1 DSP) |
8 |
2 |
|
PVDM2-32 (2 DSPs) |
16 |
4 |
|
|
PVDM2-48 (3 DSPs) |
24 |
6 |
|
|
PVDM2-64 (4 DSPs) |
32 Maximum of 50 conferences per NM |
8 |
|
|
NM-HD-1V (8 participants per conference) |
Fixed at 1 DSP |
8 conferences per NM |
2 conferences per NM |
|
NM-HD-2V (8 participants per conference) |
Fixed at 1 DSP |
8 conferences per NM |
2 conferences per NM |
|
NM-HD-2VE (8 participants per conference) |
Fixed at 3 DSPs |
24 conferences per NM |
6 conferences per NM |
Table 2-10 Conferencing DSP Resources
|
|
Conferences |
||
|
Hardware Module or Chassis |
DSP Configuration |
All Participants Use G.711 (a-law, mu-law) |
One or More Participants Use G.729 or G.729a |
|
NM-HDV |
1 to 5 of PVDM-12 |
3, 6, 9, 12, or 15 conferences per NM |
3, 6, 9, 12, or 15 conferences per NM |
|
NM-HDV-FARM (6 participants per conference) |
(3 DSPs per PVDM-12) |
||
|
1751 |
1 to 2 of: |
1 conference per DSP |
1 conference per DSP |
|
(6 participants per conference) |
PVDM-256K-4 (1 DSP) |
Maximum of 5 conferences per chassis |
Maximum of 5 conferences per chassis |
|
PVDM-256K-8 |
|||
|
(2 DSPs) |
|||
|
PVDM-256K-12 |
|||
|
(3 DSPs) |
|||
|
PVDM-256K-16HD |
|||
|
(4 DSPs) |
|||
|
PVDM-256K-20HD |
|||
|
(5 DSPs) |
|||
|
1760 |
1 to 2 of: |
1 conference per DSP |
1 conference per DSP |
|
(6 participants per conference) |
PVDM-256K-4 (1 DSP) |
Maximum of 20 conferences per chassis |
Maximum of 20 conferences per chassis |
|
PVDM-256K-8 |
|||
|
(2 DSPs) |
|||
|
PVDM-256K-12 |
|||
|
(3 DSPs) |
|||
|
PVDM-256K-16HD |
|||
|
(4 DSPs) |
|||
|
PVDM-256K-20HD |
|||
|
(5 DSPs) |
|||
|
WS-6608-T1 and WS-6608-E1 |
Fixed at 64 of C549 |
32 participants per por |
t 32 participants per port |
|
(3 to 32 participants per conference) |
(8 DSPs per port) |
G.729a and G.711 only |
|
|
WS-SVC-CMM- |
Fixed at 4 of |
128 conferences |
128 conferences per |
|
ACT | (64 participants per conference) |
Broadcom 1500 |
per module |
module |
The number of required DSPs for transcoding depends on the DSP type used and the codecs that need to be transcoded. C549 support up to four transcoding sessions for any codec combination. The C5510 supports 16 G.711 sessions; eight G.729a, ab, and GSM-FR sessions; and six G729, G729b, and GSM-E FR sessions.
Table 2-11 shows the various DSP resources that can be used for transcoding and their performance.
Table 2-11 Transcoding DSP Resources
|
|
Conferences |
||
|
Hardware Module or Chassis |
DSP Configuration |
All Participants Use G.711 (a-law, mu-law) |
One or More Participants Use G.729 or G.729a |
|
NM-HDV2 |
1 to 4 of: |
Sessions/PVDM2 |
Sessions/PVDM2 |
|
PVDM2-8 (1/2 DSP) |
8 |
4 |
|
|
PVDM2-16 (1 DSP) |
16 |
8 |
|
|
PVDM2-32 (2 DSPs) |
32 |
16 |
|
|
PVDM2-48 (3 DSPs) |
48 |
24 |
|
|
PVDM2-64 (4 DSPs) |
64 |
32 |
|
|
NM-HD-1V |
Fixed at 1 DSP |
16 sessions per NM |
8 sessions per NM |
|
NM-HD-2V |
Fixed at 1 DSP |
16 sessions per NM |
8 sessions per NM |
|
NM-HD-2VE |
Fixed at 3 DSPs |
48 sessions per NM |
24 sessions per NM |
|
NM-HDV NM-HDV-FARM |
1 to 5 of PVDM-12 (3 DSPs per PVDM-12) |
12, 24, 36, 48, or 60 sessions per NM |
12, 24, 36, 48, or 60 sessions per NM |
|
1751 |
1 to 2 of: |
2 sessions per DSP |
2 sessions per DSP |
|
PVDM-256K-4 (1 DSP) PVDM-256K-8 (2 DSPs) |
Maximum of 16 sessions per chassis |
; Maximum of 16 sessions per chassis |
|
|
PVDM-256K-12 (3 DSPs) |
|||
|
PVDM-256K-16HD (4 DSPs) |
|||
|
PVDM-256K-20HD (5 DSPs) |
|||
Table 2-11 Transcoding DSP Resources
|
|
|
Conferences |
|
|
Hardware Module or Chassis |
DSP Configuration |
All Participants Use G.711 (a-law, mu-law) |
One or More Participants Use G.729 or G.729a |
|
1760 |
1 to 2 of: |
2 sessions per DSP |
2 sessions per DSP |
|
PVDM-256K-4 |
Maximum of 20 sessions per chassis |
Maximum of 20 sessions per chassis |
|
|
(1 DSP) |
|||
|
PVDM-256K-8 |
|||
|
(2 DSPs) |
|||
|
PVDM-256K-12 |
|||
|
(3 DSPs) |
|||
|
PVDM-256K-16HD |
|||
|
(4 DSPs) |
|||
|
PVDM-256K-20HD |
|||
|
(5 DSPs) |
|||
|
WS-6608-T1 and WS-6608-E1 |
Fixed at 64 of C549 (8 DSPs per port) |
24 sessions per port |
24 sessions per port |
|
WS-SVC-CMM- |
Fixed at 4 of |
128 sessions per module |
128 sessions per module |
|
ACT |
Broadcom 1500 |
||
In addition to transcoding, DSPs can also be used as hardware MTPs. Table 2-12 shows the various DSPs that can be used as MTPs and their performance.
Table 2-12 MTP DSP Resources for Enhanced Cisco IOS Media Resources
|
Hardware Module or Chassis |
DSP Configuration |
MTP G.711 (a-law, mu-law) |
|
NM-HDV2 |
1 to 4 of: |
Sessions per PVDM: |
|
PVDM2-81 (1/2 DSP) |
8 |
|
|
PVDM2-16 (1 DSP) |
16 |
|
|
PVDM2-32 (2 DSPs) |
32 |
|
|
PVDM2-48 (3 DSPs) |
48 |
|
|
PVDM2-64 (4 DSPs) |
64 |
|
|
NM-HD-1V |
Fixed at 1 DSP |
4 sessions per NM |
Table 2-12 MTP DSP Resources for Enhanced Cisco IOS Media Resources
|
Hardware Module |
|
MTP |
|
or Chassis |
DSP Configuration |
G.711 (a-law, mu-law) |
|
NM-HD-2V |
Fixed at 1 DSP |
16 sessions per NM |
|
NM-HD-2VE |
Fixed at 3 DSPs |
48 sessions per NM |
|
WS-SVC-CMM-ACT |
Fixed at 4 of Broadcom 1500 |
256 sessions per module |
