MGCP gateway DSP issue

[simonmossman]

Hi all

I have an MGCP gateway connected to our 5.1.3 CUCM.

It seems we have exceeded our DSP's capability as users are unable to make calls out the gateway due to no channels being available. On the gateway I can see the error messages informing that there are no DSP resources available. I find this very strange as we have a full E1 card and a pvdm-32 module. when I look at the DSP's I can see that we get maxed out at 14 channels as per output below. The Telco is pointing the finger back at us but the router is configured to a use all channels 1-31.......

Any ideas on further troubleshooting before I go back to telco???

dsp 1:
  State: UP, firmware: 4.4.26
  Max signal/voice channel: 16/16
  Max credits: 240
  Group: FLEX_GROUP_VOICE, complexity: FLEX
    Shared credits: 0, reserved credits: 0
    Signaling channels allocated: 16
    Voice channels allocated: 8
    Credits used: 240
    Voice channels:
      Ch01: voice port: 0/0/0:15.23, codec: g729br8, credits allocated: 30
      Ch02: voice port: 0/0/0:15.29, codec: g729br8, credits allocated: 30
      Ch03: voice port: 0/0/0:15.15, codec: g729br8, credits allocated: 30
      Ch04: voice port: 0/0/0:15.5, codec: g729br8, credits allocated: 30
      Ch05: voice port: 0/0/0:15.8, codec: g729br8, credits allocated: 30
      Ch06: voice port: 0/0/0:15.25, codec: g729br8, credits allocated: 30
      Ch07: voice port: 0/0/0:15.26, codec: g729br8, credits allocated: 30
      Ch08: voice port: 0/0/0:15.27, codec: g729br8, credits allocated: 30
  Group: FLEX_GROUP_XCODE, complexity: MEDIUM
    Shared credits: 0, reserved credits: 0
    Transcoding channels allocated: 0
    Credits used: 0

dsp 2:
  State: UP, firmware: 4.4.26
  Max signal/voice channel: 16/16
  Max credits: 240
  Group: FLEX_GROUP_VOICE, complexity: FLEX
    Shared credits: 0, reserved credits: 0
    Signaling channels allocated: 14
    Voice channels allocated: 6
    Credits used: 180
    Voice channels:
      Ch01: voice port: 0/0/0:15.21, codec: g729br8, credits allocated: 30
      Ch02: voice port: 0/0/0:15.31, codec: g729br8, credits allocated: 30
      Ch03: voice port: 0/0/0:15.30, codec: g729br8, credits allocated: 30
      Ch04: voice port: 0/0/0:15.28, codec: g729br8, credits allocated: 30
      Ch05: voice port: 0/0/0:15.19, codec: g729br8, credits allocated: 30
      Ch06: voice port: 0/0/0:15.20, codec: g729br8, credits allocated: 30
  Group: FLEX_GROUP_XCODE, complexity: MEDIUM
    Shared credits: 0, reserved credits: 60
    Transcoding channels allocated: 0
    Credits used: 0

DSP groups on slot 1:
This command is not applicable to slot 1

[Abu Hadee · Accepted solution]

Hello Simon,

With the PVDM-32, you can make 32 G711 call, but only 16G729 call. since g729 takes more MIPS or credit, it allows you to have less number of call.

As you can see on your DSP out, each DSP have 240 credit, and each G729 calls takes 30 credit. So you can have only 8 calls per dsp. So total 16 calls.

When you configure flex type of complexity, it allows you configured the PRI timeslots based on best codec (less complexity). That is why you are allowed to configure 31 channels. But doesn't mean that you can have 32 calls if you use different codec.

I'm not sure if you can change the codec or not, but if you change to G711, you should be able to have 32 calls.

Hope this helps.

Thank you

- abu

[simonmossman]

Thanks Abu......well explained.....cheers