atcomsystems.ca/forum Forums TDM Business Telephone Systems NEC Telephones & Systems Aspire IP Phones - strange problem

Mostly just posting to see if this has happened to anyone else - I am pretty certain it's not an issue with the phone equipment.

Here's the scenario - I have an NEC Aspire M with a VoIP card. Connecting four Aspire IP sets in a different site over a routed MAN (not NAT or VPN). Phones connect just fine - but when I call extensions on the other site - or use the trunks from that site - there is a very loud 60 cycle hum heard on both ends of the call. When I move the IP phone to the site with the Aspire M PBX - everything works perfectly. Also, I can point the IP phones at the remote site to an Aspire S at annother of this companies sites - over the same routed MAN, and the site to site and CO calls are clear.

I think that surely rules out any issue with the Aspire M - or its VoIP card, or the IP phone sets.

That leaves some kind of network issue, but I cant imagine what would produce that hum on a pure data circuit..........

Hoping someone out there has seen and conquered something akin to this in the past, and can save me some time in troubleshooting.

Thanks!

Update - I switched from a small POE switch to a power injector, as some of the phones were pre 802.3af and would not come on with the switch - problem cleared with this change.

I was thinking it may be a POE/power issue as I read the post. Was lighted to see that as I scrolled down you verified it.