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Question about DSP resources

Hi All,

I have 4 E1 controllers configured in 2851 router and 3 PVDM installed as below

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NAME: "VWIC2-2MFT-T1/E1 - 2-Port RJ-48 Multiflex Trunk - T1/E1 on Slot 0 SubSlot 1", DESCR: "VWIC2-2MFT-T1/E1 - 2-Port RJ-48 Multiflex Trunk - T1/E1"

PID: VWIC2-2MFT-T1/E1  , VID: V01 , SN: FOC14515X9M

NAME: "VWIC2-2MFT-T1/E1 - 2-Port RJ-48 Multiflex Trunk - T1/E1 on Slot 0 SubSlot 2", DESCR: "VWIC2-2MFT-T1/E1 - 2-Port RJ-48 Multiflex Trunk - T1/E1"

PID: VWIC2-2MFT-T1/E1  , VID: V01 , SN: FOC140537LB

NAME: "PVDMII DSP SIMM with three DSPs on Slot 0 SubSlot 4", DESCR: "PVDMII DSP SIMM with three DSPs"

PID: PVDM2-48          , VID: V01 , SN: FOC14515DUL

NAME: "PVDMII DSP SIMM with four DSPs on Slot 0 SubSlot 5", DESCR: "PVDMII DSP SIMM with four DSPs"

PID: PVDM2-64          , VID: V01 , SN: FOC14511FKX

NAME: "PVDMII DSP SIMM with four DSPs on Slot 0 SubSlot 6", DESCR: "PVDMII DSP SIMM with four DSPs"

PID: PVDM2-64          , VID: V01 , SN: FOC14346AMV

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The gateway is configured as MGCP and the region is configured in such a way that calls use G729 for intercluster. The location is configured as 2880kbps so 120 calls of G729 can be passed.

Issue : Even if location configured for 120 calls I am seeing the gateway can take only 88 calls. Could someone let me know if this is the problem with less dsp resources? The DSPs are configured for FLEX complexity and I see all calls taking g729r8 codec to CUCM.

Call flow : PBX --> E1 --> MGCP GW --> CUCM --> SIP TRUNK --> CUCM --> IP PHONE

Please help me here.

1 ACCEPTED SOLUTION

Accepted Solutions
VIP Purple

Re: Question about DSP resources

Hi,

What I can see from the output is

a. u have total of 11 DSPs with Maximum credits available of 240 each

b. all the credits have been used  as we can see from the output

c. total voice channels allocated  are 88 i.e. 8 per dsp .Total DSPs are 11 . hence, 11x8=88 which matches your number of calls mentioned.

d. PVDM2-48 has 3 DSPs while PVDM2-64 has 4 DSPs which makes MIPS toal as 720 +960+960 and DSPs as 11.  G.729 uses 30 MIPS per call.

d. output from one of the dsp is as below which I have highlighted

dsp 12:

  State: UP, firmware: 26.3.8

  Max signal/voice channel: 16/16

  Max credits: 240

  num_of_sig_chnls_allocated: 0

  Transcoding channels allocated: 0

  Group: FLEX_GROUP_VOICE, complexity: FLEX

    Shared credits: 0, reserved credits: 0

    Signaling channels allocated: 0

    Voice channels allocated: 8

    Credits used (rounded-up): 240

    Voice channels:

      Ch01: voice port: 0/2/0:15.18, codec: g729r8, credits allocated: 30

      Ch02: voice port: 0/1/1:15.15, codec: g729r8, credits allocated: 30

      Ch03: voice port: 0/2/1:15.15, codec: g729r8, credits allocated: 30

      Ch04: voice port: 0/1/0:15.17, codec: g729r8, credits allocated: 30

      Ch05: voice port: 0/1/1:15.17, codec: g729r8, credits allocated: 30

      Ch06: voice port: 0/2/1:15.17, codec: g729r8, credits allocated: 30

      Ch07: voice port: 0/1/1:15.9, codec: g729r8, credits allocated: 30

      Ch08: voice port: 0/2/0:15.26, codec: g729r8, credits allocated: 30

regds,

aman

4 REPLIES

Re: Question about DSP resources

Logs from gateway is attached for the reference.

VIP Purple

Re: Question about DSP resources

Hi,

What I can see from the output is

a. u have total of 11 DSPs with Maximum credits available of 240 each

b. all the credits have been used  as we can see from the output

c. total voice channels allocated  are 88 i.e. 8 per dsp .Total DSPs are 11 . hence, 11x8=88 which matches your number of calls mentioned.

d. PVDM2-48 has 3 DSPs while PVDM2-64 has 4 DSPs which makes MIPS toal as 720 +960+960 and DSPs as 11.  G.729 uses 30 MIPS per call.

d. output from one of the dsp is as below which I have highlighted

dsp 12:

  State: UP, firmware: 26.3.8

  Max signal/voice channel: 16/16

  Max credits: 240

  num_of_sig_chnls_allocated: 0

  Transcoding channels allocated: 0

  Group: FLEX_GROUP_VOICE, complexity: FLEX

    Shared credits: 0, reserved credits: 0

    Signaling channels allocated: 0

    Voice channels allocated: 8

    Credits used (rounded-up): 240

    Voice channels:

      Ch01: voice port: 0/2/0:15.18, codec: g729r8, credits allocated: 30

      Ch02: voice port: 0/1/1:15.15, codec: g729r8, credits allocated: 30

      Ch03: voice port: 0/2/1:15.15, codec: g729r8, credits allocated: 30

      Ch04: voice port: 0/1/0:15.17, codec: g729r8, credits allocated: 30

      Ch05: voice port: 0/1/1:15.17, codec: g729r8, credits allocated: 30

      Ch06: voice port: 0/2/1:15.17, codec: g729r8, credits allocated: 30

      Ch07: voice port: 0/1/1:15.9, codec: g729r8, credits allocated: 30

      Ch08: voice port: 0/2/0:15.26, codec: g729r8, credits allocated: 30

regds,

aman

VIP Super Bronze

Question about DSP resources

Lajith first of all Amanso (+5) is spot on on how the dsps are used up. Great post Aman..

Second, the badnwidth allocated has nothing to do with the PRI channels available on the gateway. The PRI channels depend on the type of DSP, dsp complexity and the codec you are using for your calls. You can double your DSP capacity by using G711 codec rather than a High complexity codec like G729. Each G711 call will use 15 credits/call and that will mean you have 16 channels per dsp which will give you a total of 16*11 (176 calls)

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VIP Purple

Question about DSP resources

Hi Aok,

Thanks for the ratings.

[+5] for providing more info.

regds,

aman

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