IP phones keep droping - HELP!

[nsanto17]

I have two people working in a remote office using IP Phones. They are connected to our office via two Netgear VPN routers. Everything has been working fine for a long time. Over the past few weeks her phones have been dropping and then re-connect in about 30 secs.

I have seen her phones drop and the wierd thing is that the tunnel never goes down. I have been monitoring the tunnel and that stays up but the phones still drop. Is there anything i am missing? Any help would be great.

Thanks

Nick

 

[nsanto17]

Sorry i should have provided this info.

BCM450
Nortel IP2002 phones.
Tunnel is over internet not MPLS.

We have another office connected via MPLS and their phones have been just fine.

 

[z3r0cool]

We had a similar problem with phones on a point to point VPN after turning on an IPS. It wasn't blocking all of the VoIP traffic, but every so often it would filter enough packets to kill the connection.