BCM50 loses network connection on VOIP calls?

[SCFG]

We have a BCM 400 in our head office and a BCM 50 in our satellite office. They're connected through a 5Mbps "private ethernet" from our ISP (basically we have normal switches on each end, plug in the ethernet cable from the ISP's device, and the two offices are on the same subnet). The BCM's are set up with 12 VOIP lines on each end so that we can extension call from one office to the other.

The problem we're having is that the BCM50 will sometimes disconnect completely from our network sometimes when we initiate a VOIP call either way. We would get a long pause and then a busy tone. I'm constantly pinging the BCM50 and when this happens it will stop responding to ping requests. After a little while (sometimes a minute, sometimes several minutes) the BCM50 will come back up.

Any ideas on what the problem could be?

All other traffic on that "private ethernet" is limited to 2Mbps so there's 3Mbps available for the BCMs.

The BCM50 is on system software version 6.0.2.05.237 and the BCM400 on 4.0.2.21d.

 

[Dasheen]

Fully patched?

Is the voice in a separate vlan from the data?

What codec?

 

[SCFG]

Yes, fully patched as of a couple weeks ago.

The voice and data are not on separate VLANs (the service provider says we can't run our own VLANs on that private ethernet connection). I've limited the data to 2Mb, allowing 3Mb for voice but I know this isn't ideal. I'm open to suggestions on this though.

Under IP Trunks, SIP Media parameters it shows G.729 and G.711-uLaw selected. Under H323 Media Parameters it shows G.729, G.723, G.711-uLaw and G.711-aLaw selected.

 

[desphoneguy]

Are you using a BCM50e?

If so I has the same problem. The internal router will drop the VPN when it sees oneway traffic after 2 minutes. No matter what you set the timers for. This, I am told is a safety net because the router thinks it is being attacked.

In the VPN advanced settings setup a ping to the remote site. This will keep the VPN up and running based on the timers that you set.

Also just a note change the order of the codec so that the first choice is G711. This will give you much better voice quality