SIP Trunk Redundancy

[mattiep00]

Hi, I am wondering the following:

If we configure a SIP trunk, and on the providor equipment they specify the trunk IP Address (I assume of the Publisher) what happens in the event of a publisher failure? How will calls be made over the trunk?

Can anyone give me some ideas, or if there will be any redundancy in the event of a publisher outage?

Thanks!

[virverma]

If a SIP trunk failure or ip interface failure occurs, backup PSTN lines connected directly to cisco SRST can be used for PSTN access.

Please check this link,

check "failover and redundancy"

http://www.cisco.com/en/US/solutions/collateral/ns340/ns517/ns431/SIP_trunk__SRND.pdf

[mattiep00]

Thanks for the link I will go through it in further detail tomorrow. However on a quick glance through, it doesn't seem to answer the problem of what happens if the trunk configured IP Address of the publisher is unavailable (publisher outage)...

[KonradStepniewski]

Then depends of configuration on SP side, if they have just one IP configured SIP trunk will be down. Your incoming calls on SIP trunk wont wont work, but you still will be able to call via PSTN if you have it configured.

If they have subscriber IP configured as second option then you good.

[mattiep00]

I am led to believe that SP side is only able to configure a single IP Address though - is that not correct?

[KonradStepniewski]

No idea, check with them...