SRST Load balancing Design

[shane.oconnell]

Hello -

Tech in use: CUCM v8.6 and MGCP Gateways 3945's (x 2)

I want to load balance SRST across two branch ISR routers, lets say GW01 and GW02. I will have 1 inbound PRI connected to each gateway and a DDi range will be load balanced across both PRIs. So on the DDi range and inbound call could enter on either gateway (as the calls will be load balanced)

To achieve it my SRST design, I would likely create two device pools and put half of my phones into one DP and the other half in the second DP.

The bit that I am stuck with is on the inbound calls. So for example, if a call comes into GW01 for ext 2001 but my phone that has extension 2001 is actually registered to GW02 - then how do I handle this? How do I send the call destined for ext 2001 over to the other gateway?

Any thoughts ?

[Chris Deren · Accepted solution]

You can configure a dial-peer on each GW to point to the other router in case the dialed number is not found locally, the issue you may run into is potential for loops if the extension is not defined on neither side, so your dial-peers may need to be very specific.

HTH,

Chris

[shane.oconnell]

Thanks Chris. Would you have an example for the dial-peer by any chance?

[Dennis Mink · Accepted solution]

lets say for argument;s sake that 2XXX  summarised your DID range. If a call comes into GW01 for 2001 and 2001 is registered on GW2, you will need a dial peer from GW01 to point to GW02  with 2xxx as the destination pattern. If a call comes into GW01 for 2002 and 2002 is registered on GW01, it will route the call to that SRST registered phone, because it is the longest match.

easy.,

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[problemchild27 · Accepted solution]

Hi,

   Lets have DN 2001 & 2002

- 2001 is in DP1 registered to GW1

- 2002 is in DP2 registered to GW2

- The PSTN PRI is terminiated in GW1

now someone calls 2002, GW looks for the registered phones first, no registration, looks for the dial-peer, which is

Dial-peer voice xx pots

destination-pattern 2002

session-targe ipv4:x.x.x.x (ip address of the GW2)

dtmf-relay h245-alphanumeric

codec (as per your standard)

Thankyou

     PC