Gatekeeper rejected a call initiated by the IP PBX behind 4351-x/K9 on MPLS transport

[amit_temkar]

There is a branch site with Cisco ISR4351-AX/K9 router and MPLS link.
There is an IP PBX behind Cisco 4351. The IOS version of 4351 is "isr4300-universalk9.16.09.06.SPA.bin"
At other end of MPLS, there's a Gatekeeper.

The Gatekeeper is rejecting the call initiated by the IP PBX from branch. It seems that IP PBX is using G.729 codec and Gatekeeper is also tuned to have G.729, however it seems with putting 4351-AX/K9, the codec is getting changed to G.711 which Gatekeeper is not accepting. This is not clear yet and 4351 with MPLS is acting just as transport with no config to have any specific CODEC.
bandwidthReject : {
requestSeqNum 57021,
rejectReason invalidPermission : NULL,
allowedBandWidth 0
}

Also when we put 3945 router with IOS "c3900-universalk9-mz.SPA.151-4.M4.bin", the session gets established.

The config is exactly same in 3945 and 4351 and we are using H.323 protocol.

Want to know if anyone witnessed similar issue somewhere?

[Nithin Eluvathingal]

That could be due to the Toll Fraud Enhancements on ios. Add required ip under Voice service voip.

An Example configuration.

voice service voip
ip address trusted list
ipv4 10.10.0.0 255.255.0.0

[amit_temkar]

Thanks for the response Nitin,

Do you mean to say that this command will be needed at gatekeeper end since there is no voip service on router. router and MPLS is just acting as a transport media.

Also are you referring Toll Fraud Enhancements on 4351 IOS being a new router.

[Nithin Eluvathingal]

It’s a enhancement on iOS to avoid tall fraud.

For a test purpose Apply below command on isr  4351 and see if call works.

voice service voip
no ip address trusted list>> this diable  this feature.

You can learn more from below link

https://community.cisco.com/t5/collaboration-voice-and-video/understanding-toll-fraud-enhancements-in-15-1-2-t/ta-p/3123167