I have a SIP Phone system here in my office. When on the same switch as my sip phone server, I am sitting here calling from my computer to my cell phone with my direct SIP software and it works perfectly.
When I setup the SIP phone software in OpenFire and setup Spark to use it, I can call my cell phone, and on my laptop through Spark, I can hear perfectly. when I lean down to my laptop to speak from Spark to my cell, I can barely understand myself on my cell, and I hear more static than my voice.
I have tried to play with the codecs in the Spark, but every one of them has the same issue. My OpenFire install is on the same server as my SIP server so I would have a hard time believing that it could be network related. As I said, it works perfectly fine when I have my regular SIP phone software here on my laptop, connected directly to my SIP server (whether on the WAN or the LAN), but the moment I connect up Spark to use my SIP Server, I get horrible static. I have spent a couple days on this issue, and have read through a bunch of articles, but I cannot reduce the static noise at all.
This is a brand new install of OpenFire + Spark. We did not have an IM platform before and are moving that way. I wanted to see if I could combine Spark with my current SIP SoftPhone so I did not have to have 2 pieces of software to run it. OpenFire + Spark works great. We have WAN and LAN IM communication and there are no issues there.