Phone Failover via WAN

[Ahmed Adeyemi]

I am running a system clustering multisite over WAN (HQ, Site 1, Site 2). Each of the sites are connected to the HQ via WAN.

In each of the site, i have 2 subscribers and in the HQ, i have 1 Pub and 2 Subs

I originally have 1 MPLS circuit which works perfectly fine. Now we introduced a second circuit which individually works fine as well. 

A phone in site 1 makes a call to another cluster via ICT that goes back to another cluster. When the network guys conduct a failover by shutting down/unplugging the primary circuit, the call becomes a one-way audio (Site 1 can here HQ, but HQ cannot here site 1). It takes about 2 minutes for the data path to get re-established but the call never gets re-established. Sometimes, i see the phone display "Temp Fail" but still maintains the one-way audio. Regardless of how long i wait, i still experience this. But if i hang up the call and make a new call, i get 2-way audio. Does anyone know what the issue could be or has anyone experienced similar issue?  

[Dennis Mink · Accepted solution]

The temp fail message on your phones are an indication that an RTP stream being interrupted/broken. which is caused by manually failing over the path over which your existing RTP stream is going. When this path fails, and correct me if I am wrong, phones do not re-signal to get a new RTP path establish as part of the same initial call. Only until your routing converges to the fail over path, can you make the call again and will iut get established across the "new" path. As far as I know there is no mid call mechanism either with SIP or SCCP that renegotiates media if they are lost during the call. To me this is expected behavior.

In general,1 way audio is normally caused by one way routing or ACL's

[Terry Cheema · Accepted solution]

Just noticed there are duplicate threads on the same topic: https://supportforums.cisco.com/discussion/12614566/phone-failover-wan

Dennis is pretty much right (+5)

-Terry

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[Ahmed Adeyemi]

Thanks, did;t know the post was in there twice.