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01-09-2013 03:32 PM - edited 03-12-2019 09:56 AM
Understanding the Output of "show voice dsp group all"
This document should be used inconjuction with the "Cisco PVDM2 and PVDM3 DSP Credit/MIPS Allocation" to get the best of both. The link below can be used to access the mentioned doc
https://supportforums.cisco.com/docs/DOC-29164
INTRODUCTION:
The show voice dsp group all command is a powerful ios command to view details of dsps on a gateway. This short document attempts to explain the meaning of each of the output of this command. For clarity each output has been numbered. These numbers will be referenced within the document to explain the meaning if the corresponding line. Lets dive in
#sh voice dsp group all
DSP groups on slot 0:
dsp 1:
State: UP, firmware: 28.3.3……………………………………………………………………………..1
Max signal/voice channel: 43/43..........................................................................................2
Max credits: 645, Voice credits: 645, Video credits: 0……………………………………..............3
num_of_sig_chnls_allocated: 43…………………………………………………………………….....4
Transcoding channels allocated: 0……………………………………………………………………..5
Group: FLEX_GROUP_VOICE, complexity: FLEX………………………………………………......6
Shared credits: 555, reserved credits: 0…………………………………………………………........7
Signaling channels allocated: 43…………………………………………………………………….....8
Voice channels allocated: 6………………………………………………………………………….....9
Credits used (rounded-up): 90………………………………………………………………………....10
Voice channels: …………………………………………………………………………………………11
Ch01: voice port: 0/0/0:15.1, codec: g711ulaw, credits allocated: 15
Ch02: voice port: 0/0/0:15.2, codec: g711ulaw, credits allocated: 15
Ch03: voice port: 0/0/0:15.3, codec: g711ulaw, credits allocated: 15
Ch04: voice port: 0/0/0:15.4, codec: g711ulaw, credits allocated: 15
Ch05: voice port: 0/0/0:15.5, codec: g711ulaw, credits allocated: 15
Ch06: voice port: 0/0/0:15.6, codec: g711ulaw, credits allocated: 15
Slot: 0 ……………………………………………………………………………………………………12
Device idx: 0
PVDM Slot: 0 ……………………………………………………………………………………………13
Dsp Type: SP2600 ……………………………………………………………………………………..14
dsp 2:
State: UP, firmware: 28.3.3
Max signal/voice channel: 43/43
Max credits: 645, Voice credits: 645, Video credits: 0
num_of_sig_chnls_allocated: 17…………………………………………………………………….....15
Transcoding channels allocated: 12……………………………………………………………….......16
Group: FLEX_GROUP_VOICE, complexity: FLEX
Shared credits: 258, reserved credits: 0
Signaling channels allocated: 17..........................................................................................17
Voice channels allocated: 0
Credits used (rounded-up): 0
Group: FLEX_GROUP_XCODE, complexity: HIGH…………………………………………...........18
Shared credits: 0, reserved credits: 387 ……………………………………………………..............19
Transcoding channels allocated: 3 ………………………………………………………………........20
Credits used (rounded-up): 97……………………………………………………………………......21
Slot: 0
Device idx: 0
PVDM Slot: 0
Dsp Type: SP2600
dsp 3:
State: UP, firmware: 28.3.3
Max signal/voice channel: 42/43……………………………………………………………………....22
Max credits: 645, Voice credits: 645, Video credits: 0
num_of_sig_chnls_allocated: 0 ……………………………………………………………………….23
Transcoding channels allocated: 8 …………………………………………………………………...24
Group: FLEX_GROUP_VOICE, complexity: FLEX
Shared credits: 18, reserved credits: 0
Signaling channels allocated: 0……………………………………………………………………….25
Voice channels allocated: 0
Credits used (rounded-up): 0
Group: FLEX_GROUP_CONF, complexity: CONFERENCE……………………………………...26
Shared credits: 0, reserved credits: 369 …………………………………………………………….27
Codec: CONF_G729, maximum participants: 8 ……………………………………………….......28
Sessions per dsp: 7 …………………………………………………………………………………...29
Group: FLEX_GROUP_XCODE, complexity: HIGH-------------------------------------------------------------30
Shared credits: 0, reserved credits: 258-----------------------------------------------------------------------------31
Transcoding channels allocated: 3------------------------------------------------------------------------------------32
Credits used (rounded-up): 97-------------------------------------------------------------------------------------------33
Slot: 0
Device idx: 0
PVDM Slot: 0
Dsp Type: SP2600
Lines output Explained
1. Line 1
State: UP, firmware: 28.3.3
This basically shows the status of the dsp and the firmware loaded on it. This is very useful because while troubleshooting it is good to know the state of the dsp.
E.g, the output below shows a failed dsp state which suggests that all calls terminated on this dsp will also fail
Router#show voice dsp group all
DSP groups on slot 0:
dsp 1:
State: FAIL, firmware: 0.0.0
Max signal/voice channel: 8/8
Max credits: 160
num_of_sig_chnls_allocated: 4
Transcoding channels allocated: 0
Group: FLEX_GROUP_VOICE, complexity: FLEX
Shared credits: 160, reserved credits: 0
Signaling channels allocated: 4
Voice channels allocated: 0
Credits used (rounded-up): 0
2. Line 2 and Line 21
Max signal/voice channel: 43/43 and Max signal/voice channel: 42/43
Max signal: is the total available channel for use on this particular dsp.
Voice channel: is the designed total available channel for use on this type of dsp based on its credit allocation
Let me explain this a little bit...
Look at this PVDM3-128, this PVDM has 3 dsps with a total of 128 channels...
The output of. Pay attention to the dsp 3.
sh voice dsp group all:
DSP groups on slot 0:
dsp 1:
State: UP, firmware: 28.3.3
Max signal/voice channel: 43/43
------------------------------------Other-Output and that of dsp 2 truncated
dsp 3:
State: UP, firmware: 28.3.3
Max signal/voice channel: 42/43------------------here you see the max signal=42 (this is because 43+43=86, hence we only have 42 channels left to make 128 channels)..dsp1 has 43 channels, dsp 2 has 43, hence dsp 3 will have 42.
3. Line 3
Max credits: 645, Voice credits: 645, Video credits: 0
Max Credits:
PVDM3 and PVDM2 DSP modules use a credit-based system. Each module is assigned a fixed number of "credits" that represent a measure of its capacity to process media streams. Each media operation, such as voice termination, transcoding, and so forth, is assigned a cost in terms of credits. As DSP resources are allocated for a media processing function, its cost value is subtracted from the available credits. A DSP module runs out of capacity when the available credits run out and are no longer sufficient for the requested operation
Voice Credits and Video Credits:
PVDM 3 is the first cisco set of DSPs that support both voice and video. The line displays the amount of credit allocated to voice and video. In the output above all available credit on this dsp was allocated to voice.
In the output blow some credits were allocated to video
#show dsp-group all
DSP groups on slot 0:
dsp 1:
State: UP, firmware: 31.1.0
Max signal/voice channel: 32/32
Max credits: 480, Voice credits: 15, Video credits: 465
num_of_sig_chnls_allocated: 0
Transcoding channels allocated: 0
Group: FLEX_GROUP_VIDEO_POOL, complexity: FLEX
Video Credits Max: 465, Share: 465, Reserved (rounded-up): 0
4. Line 4 and 8
num_of_sig_chnls_allocated: 43
Signaling channels allocated: 43
This line shows the total allocated voice channels that this dsp will handle. This value is computed based on the max credit available, the codec complexity mode and the number of pri/voice-ports configured on the gateway.
Example: Gateway with PVDM3-128 and 60 Pri channels configurd. Flex dsp mode.
Each dsp on PVDM3-128 has 645 credit, and since this is configured for flex mode. Each channel use 15credits (G11). Hence we will have 645/15=43.
So DSP1 will be allocated the whole 43 channel (line 4 and 8)
DSP2 will then be allocated the remaining 17 channels totalling 60. (line 15 and 17)
DSP3 is not allocated any voice channels because there no more channels required (Line 22 and 23)
5. Line 5 and 16
Dsp1
Transcoding channels allocated: 0
Dsp2
Transcoding channels allocated: 12
The transcoding channels display the total amount of channels reserved for transcoding. From the example above, DSP1 was not allocated any transcoding channels, hence this dsp will not be involved in transcoding.
DSP2 was allocated 12 channels for 12 sessions.
6. Line 6, Line 18 and Line 26
Dsp1
Group: FLEX_GROUP_VOICE, complexity: FLEX
Shared credits: 555, reserved credits: 0
Dsp2
Group: FLEX_GROUP_VOICE, complexity: FLEX
Shared credits: 258, reserved credits: 0
Group: FLEX_GROUP_XCODE, complexity: HIGH
Shared credits: 0, reserved credits: 387
Dsp3
Group: FLEX_GROUP_XCODE, complexity: HIGH
Shared credits: 0, reserved credits: 258
Group: FLEX_GROUP_CONF, complexity: CONFERENCE
Shared credits: 0, reserved credits: 369
These outputs display the type of resources each dsp is used for. On dsp2, we see that it is used for both voice and transcoding, while dsp3 is used for transcoding and conferencing.
Credits used for voice are shared while conferencing and transcoding always have credits reserved based on the number of sessions configured.
NB: This is one of the major differences between PVDM2 and PVDM3. On dsps of the PVDM2, a dsp reserved for conferencing can’t be used for any other purpose.
7. Line 9, 10,Line 11
Voice channels allocated: 6
Credits used (rounded-up): 90
Voice channels:
Ch01: voice port: 0/0/0:15.1, codec: g711ulaw, credits allocated: 15
Ch02: voice port: 0/0/0:15.2, codec: g711ulaw, credits allocated: 15
Ch03: voice port: 0/0/0:15.3, codec: g711ulaw, credits allocated: 15
Ch04: voice port: 0/0/0:15.4, codec: g711ulaw, credits allocated: 15
Ch05: voice port: 0/0/0:15.5, codec: g711ulaw, credits allocated: 15
Ch06: voice port: 0/0/0:15.6, codec: g711ulaw, credits allocated: 15
The voice channels allocated: display the total amount of active calls on the dsp. In this example there are six calls
Credits used: display the total of credits used up based on the total amount of calls.
Voice channels: display the voice ports used for each call, the codec used and credit used up
8. Line 12, 13 and 14
Slot: 0 -----------------------------------------This is the slot on the motherboard of the gateway
PVDM Slot: 0 --------------------------------This is the PVDM slot on slot 0
Dsp Type: SP2600 --------------------This is the dsp type. This line is only seen on the PVDM3, it’s not available on PVDM2
9. Line 28,
Codec: CONF_G729, maximum participants: 8
This specify the tye of Conference configured and the maximum particiapnts/conference
10. Line 29
Sessions per dsp: 7
This displays the total number of G729 conference that can be supported on this dsp, assuming that all credits available to this dsp are available.
This is how this number is calculated:
Each dsp on this PVDM has 645 credits. Each G729 Conference uses 92credits,
Hence 645/92 = 7.
In this example only 369 credits were available because 258 were allocated for transcoding.
Hence only a total of 4 sessions can be supported.
11. Line 30,31,32,33
Group: FLEX_GROUP_XCODE, complexity: HIGH---------------------------------------------------------This is xcoder complexity
Shared credits: 0, reserved credits: 258---------------------------------------------------------- This is the total amount of xcoding credits allocated to this DSP
Transcoding channels allocated: 3-------------------------------------------------------------------This is the total xcoding channels in use at the moment
Credits used (rounded-up): 97-------------------------------------------------------------------------This is the total credits used by the 3 xcoding channels in use.
This output displays the active xcoding channels in use on this dsp at the time of this command. It shows the xcoding complexity configured (High), it also shows the total amount of dsp credit allocated to this dsp. Note that this credit is totally reserved for xcoding. It also displays the active xcoding session/channels in use. We can see that a total of 3 is in use and the total amount of credit used up by this sessions is 97.
On a high complexity xcoding codec, each xcoding session uses about 32.33 credits..hence 3 xcoding channels will use 32.33*3 =rounded up to 97.
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Ayodeji,
Informative ! Thanks for sharing.
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Thanks for sharing.
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Very useful, Thank you for sharing,

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so interesting to read such analysis !!! Thanks :-)
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muy bueno , gracias!
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Very helpful Ayodeji thanks for posting this.

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Great Content!!! Thanks for posting!!
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Fantastic explanation!!
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Thanks for the information, it's really helpful~!!!