spanning-tree convergence

[jack samuel]

Hello,

I have the attached topology,

I have created Interface BVI1 on the router to achieve the redundancy for the core switches,if incase any of the core switches fail the voice call shouldn't get disconnect,  Hence the failover is working fine if i disconnect gig0/0 on switch A  the voice call continues without any disruption from switch B but when i revert means when i enable the port gig0/0 on switch A there is no voice for 6 to 8 sec.

How i can avoid this 6 to 8 sec disruption of voice any hints please.

Thanks
 

[Jon Marshall]

Why have you set it up like this ?

You are running HSRP on your switches which suggests they are L3 switches which means you can connect the router to each switch using a P2P link ie. each link uses a different IP subnet.

That way the router sees two equal cost paths to the voice subnet and as long as you peer between the L3 switches if the link from the active switch to the router fails then that switch should see a route to any remote destinations via the other switch.

That way you eliminate the need for STP between the switches and the router.

And a L3 routing protocol will converge a lot quicker.

Jon

[visitor68]

Agree 100% with Jon...always try to mitigate the L2 domain as it brings with it more complications and considerations to be made.

[jack samuel]

Dear Jon,

Thanks for the reply, and i tried as per your suggestion but when the voice gateway re registers (MGCP) to CUCM with another interface the call doesn't disconnects  but there is one way audio to existing call, but if i initiate a new call from another IP phone there are no issues for send/receive of audio call.

I configured EIGRP protocol and the backup comes in the routing table as soon as the primary path fails this re registers the voice gateway with another interface but creates a problem to the existing on going calls with one way audio.

so the problem still persist for the current call while failover happens. Is there any thing can be done on the router to use 1 ip address instead of 2 ip address as what we did for BVI but without spanning tree convergence.