SCN link parameters

[dagwoodsystems]

I have a six-site SCN with links of varying quality. Three of the sites are fine, two are iffy at times and one seems to break every day to where the link--as seen from SSA--goes down multiple times.

I have shared with the external IT company about disabling SIP ALG and H.323 inspection and asked them to make sure that the RTP port range (found under LAN > VOIP tab) is forwarded appropriately. That said, I am still getting no audio on some calls and horrible QOS numbers. The telcos keep talking about their facilities being fiber and coax so it certainly can't be them.

Links are used also for databases and possibly drive mapping as well but there are no VLAN controls. "The software works fine!" (forgetting that the application layer won't show delays the same way voice will). Anyway...

It has been suggested that I "skinny up" my side of the street. In other words, I change the transport protocol to client/server from the default of Avaya Proprietary. Uncheck "Allow Direct Media Path" and strap all calls to use G.729a only. This seems like a desperate move to try to get around what is surely a nagging VPN parameter.

Any thoughts on this?

Tim Alberstein

 

[IPOTS]

A network analysis is in order to really prove where the issues lies. Without it, there is nothing but finger pointing.
Most companies decline the network analysis and when QOS issues arise you are stuck proving it.

 

[dagwoodsystems]

I inherited this network and am not sure why the port ranges were skewed. Some were 46750-50750 and others were 49152-53246. Once this was ironed out, the audio problems disappeared (I also turned off Direct Media Path at all levels.

Tim Alberstein

 

[IPOTS]

I had a similar issue where voicemail greetings didn't play audio. Same thing, ports need to be 46750-50750. Someone changed them.

 

[dagwoodsystems]

I had initially run through each switch and used the 49152 range and asked the IT eggheads to follow me. Even though I maintained these parms at all sites, the SIP phones were mad. Dropping everyone back to the 46xxx fixed it. You'd think the switch would pay attention to what you shoved it in there, but maybe not. Reboot and then FM (Friggin Magic).

Tim Alberstein