Weird MPLS DTMF issue to SIP AAC

[lopes1211]

We have about 50 G450's at 20 locations on CM6.3. All G450 firmware, and network-regions are identical. All phones are digital. We have 2 different WAN connections. Half of the sites connect to the main via MPLS, half use SES/TransLAN. Both WAN connections are inside the FW.

DTMF works fine between all sites, trunks, phones, and to the h323 connected CMM at the Core.
Only sites using the SES WAN calling to AAC at the core have working DTMF (which is connected SIP through Session Manager at the core)
Sites using the MPLS WAN calling to AAC have no DTMF at all to AAC (can't even break through the voice asking for conf ID).

Since the Avaya hardware, firmware, software, endpoints are all the same for all working and non-working sites......with the only difference being the WAN connection.... it would seem this would be WAN/MPLS related? Where should we look to troubleshoot since I thought the MPLS should just pass whatever data we're sending over it. And it's passing the DTMF just fine to the h323 CMM. Head scratcher!!!

-CL

 

[kyle555]

I know there was 1 firmware version of G450 that didn't hear DTMF good

Otherwise, presuming you're DTMF to AAC is RFC2833 in the RTP stream, you'd need a pcap of the audio hitting AAC. I think there's a filter like rtp.event that will separate the RTP packets of g.711u from DTMF event.

 

[lopes1211]

Just circling back to post the resolution.

Remote (vlan30) - MPLS - MPLSrtr - SM (vlan1) - AAC (vlan4) had voice but no DTMF

The issue was that the MPLS router had no route to vlan4 AAC. This didn't matter for the voice traffic since the voice was passing through the SM via vlan1, then on to vlan4. DTMF out-of-band however was jumping right from the MPLSrtr to AAC bypassing SM and failing. Once a vlan4 route was added in the router..... DTMF success.

-CL

 

[kyle555]

Thats exceptionally weird. RTP doesn't go through SM! I'd expect it to be the same RTP IP/port/stream for voice and for 2833 dtmf whether the source is a phone or a gateway.