sundance-communications.com/forum Forums TDM Business Telephone Systems Samsung Telephones & Systems Poor quality on SPNET

We have a customer with 2 7100's (4.70) linked with SPnet. They have terrible quality on SIP calls transferred from one site to another. It is setup with Port fowarding through public network. Was thinking of setting up a simple VPN. Anyone else had similar issues?

I have 2 system on a VPN, with codec G.729a, it was better then G.711a or u. Try changing the codec maybe that will help. But my sound is not perfect ...

What codecs do you have setup for SIP and SPNET?

I remember seeing something a few years ago about sip calls being transfered via GSM (or vice versa) due to GSM being compressed and using G.729a as it's also compressed.

Since your using the internet your most likely using G.729 for both sip and SPNET so it's doubly compressed (at least with MPS it's not converted to TDM and back again)

Try changing 1 to G.711 and see if that makes a difference.

Setting up a vpn will add more over head to the routers, but also reduce it at the same time due to less packets traversing the NAT tables.

Both systems are currently set to G711, both adsl services are dedicated, not sharing with any data. I may play around with codecs and do a few traces. Sites are about 500m apart, worst case we can setup a wireless link.