one way / no way audio

[pkello]

We have a new implementation of IPO and data switches, with no firewall between the IPO & data switches.

On an IPO 6.0.18.03 I have ISDN 30 (PRI-ETSI) with clocking set to network. All phones are configured with direct media path ticked (enabled by default).
The phones are Avaya 1608 H323 sets. If one way speech is encountered when making a call into or out of the IPO (via the ISDN), what is the recommended course of action to troubleshoot and resolve? There are no product notices that I found, no later 6.0 version, and no known issues that I am aware of.

The phone signalling appears normal (i.e. dial tone and ring tone as expected). If one way or no way audio intermittently occurs, this suggests a media problem (i.e. voice path, possibly the IPO itself, the network or the phone). How do we resolve?

[pdgavin]

Since the 16xx phones are on the packet bus and since the ISDN trunks are on the TDM bus you will always need a VCM channel. It does not matter if you have direct media path ticked (enabled ). That would only come into play if you had 2 IP devices like 2 IP Phones or an IP Phone and an IP trunk both set to the same codec and both with allow direct media enabled then it could go IP to IP without a VCM resource but since you have 1 IP device and 1 TDM device you will require a VCM resource. This problem is usually a networking issue. It could be a duplicate IP address or a port redirection issue or any network related issue. I suppose it could also be a bad VCM card but that would be highly unusual. You would trouble shoot it by using Sysmon and SSA and probably also a packet sniffer like wire shark. Pay attention to the MAC address of the phone and the IP Office and make sure that the packets are going where they are supposed to and not to another device that has the same IP address as the phone or the IP Office. If it is possible try to isolate the IP Office and the phones by them selves without anything else on the network and see if the problem goes away otherwise you will have to do some network troubleshooting.