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jwink
New Contributor III

SIP fail to analog - HA mode

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Hello all, I have a two part question on the 6355

Scenario 1 is:  I have SIP phones hanging off the 6355 in a hosted situation and I want my SIP trunks to fail to an analog port for 911 and am having trouble in certain cases.  I need to understand what triggers the failover and why and how it works.

Scenario 2 is:  I  want to be able to run this (the 6355) in high availability mode with another unit.   Does someone have a sample config with some explanation?

This has proven to be one of the best resources and I appreciate the assistance.

Thanks,

Jim

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Anonymous
Not applicable

Re: SIP fail to analog - HA mode

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Jim,

Thanks for posting!  The SIP proxy fail-over or "survivability" feature is triggered by the unit seeing three SIP Invites with no response.  When no response is seen from the SIP server, the unit looks for locally configured trunks to which the call can be routed.  For 911 calls, we sometimes use the following command to make sure that calls are routed by the local switchboard immediately, without being sent out to the SIP server.


sip proxy emergency-call-routing accept 911


This would be used when a local TDM trunk should be used for the call.  You may also want to read about the SIP Proxy Monitor feature in the following linked guide, .  It works only in Stateful mode, but uses a SIP Options message to determine if the a primary SIP server is unreachable and a backup SIP server should be used.

Regarding your question about "high availability", this means different things to different people.  What protocols are you hoping to implement?  We would likely need to see a network diagram to see exactly what types of scenarios you are trying to mitigate.  We do have a guide which goes over VRRP, Configuring IPv4 VRRPv2 in AOS,however this might not be the best solution in this case, since the switch and router are built together.  Failover based on default router failure is likely to require switching phones to a new router/switch.  This might be something best discussed over the phone, so feel free to call Technical Support at 888-423-8726 to open up a support ticket.


Thanks!

David


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3 Replies
Anonymous
Not applicable

Re: SIP fail to analog - HA mode

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Jim,

Thanks for posting!  The SIP proxy fail-over or "survivability" feature is triggered by the unit seeing three SIP Invites with no response.  When no response is seen from the SIP server, the unit looks for locally configured trunks to which the call can be routed.  For 911 calls, we sometimes use the following command to make sure that calls are routed by the local switchboard immediately, without being sent out to the SIP server.


sip proxy emergency-call-routing accept 911


This would be used when a local TDM trunk should be used for the call.  You may also want to read about the SIP Proxy Monitor feature in the following linked guide, .  It works only in Stateful mode, but uses a SIP Options message to determine if the a primary SIP server is unreachable and a backup SIP server should be used.

Regarding your question about "high availability", this means different things to different people.  What protocols are you hoping to implement?  We would likely need to see a network diagram to see exactly what types of scenarios you are trying to mitigate.  We do have a guide which goes over VRRP, Configuring IPv4 VRRPv2 in AOS,however this might not be the best solution in this case, since the switch and router are built together.  Failover based on default router failure is likely to require switching phones to a new router/switch.  This might be something best discussed over the phone, so feel free to call Technical Support at 888-423-8726 to open up a support ticket.


Thanks!

David


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jwink
New Contributor III

Re: SIP fail to analog - HA mode

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David,

Thanks so much. That was very helpful. The instance I am using HA is

with 908e's now. But it's good to know the 6355 will do that too, same OS

anyway. We're really just using those as a gateway device and have been

replaced with the 908s. I'll take the 911 command below to our lab for

testing.

Best regards,

Jim Winkleblack

Sales Engineer IV

Consolidated Communications

217-258-2928 Ofc

217-254-5330 Cell

Jim.Winkleblack@consolidated.com

Anonymous
Not applicable

Re: SIP fail to analog - HA mode

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Jim,

I went ahead and flagged the "Correct Answer" on this post to make it more visible and help other members of the community find solutions more easily. If you don't feel like the answer I marked was correct, feel free to come back to this post and unmark it.  If you still need assistance, we would be more than happy to continue working with you on this - just let us know in a reply.

Thanks,

David