Never used that perticular client.
However, since Open Source clients are available for Linux/
Windows/java, I usually compile something of my own.
Or you can install Asterisk (Not it works on Windows as well). Asterisk will serve as a proxy to your SIP server, and has decent support for codecs. Almost all clients will work fine with Asterisk. This way you can use pretty much any codec without changing your client.
On latency, we have to give up anyways.
Have a look at ping stats from my MTNL connection.
C:\>ping sphone.vopr.vonage.netPinging sphone.vopr.vonage.net [216.115.20.41] with 32 bytes of data:Reply from 216.115.20.41: bytes=32 time=217ms TTL=50Reply from 216.115.20.41: bytes=32 time=216ms TTL=50Reply from 216.115.20.41: bytes=32 time=218ms TTL=50Reply from 216.115.20.41: bytes=32 time=217ms TTL=50Ping statistics for 216.115.20.41: Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),Approximate round trip times in milli-seconds: Minimum = 216ms, Maximum = 218ms, Average = 217msC:\>ping 192.168.55.1Pinging 192.168.55.1 with 32 bytes of data:Reply from 192.168.55.1: bytes=32 time=2ms TTL=64Reply from 192.168.55.1: bytes=32 time=2ms TTL=64Reply from 192.168.55.1: bytes=32 time=2ms TTL=64Reply from 192.168.55.1: bytes=32 time=2ms TTL=64Ping statistics for 192.168.55.1: Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),Approximate round trip times in milli-seconds: Minimum = 2ms, Maximum = 2ms, Average = 2ms
So, WiFi adss less then 1% in terms of latency.
OTOH, this what IEEE specs say on VOIP QOS:
#Voice traffic should be marked to DSCP EF per the QoS Baseline and RFC 3246.
#Loss should be no more than 1 percent.
#One-way latency (mouth to ear) should be no more than 150 ms.[/b]
But overall, since default ping times are > 200 ms, you will never get POTS quality transmission irrespective of codec. If yo uswitch to a TCP based proxy instead of IP based, you can get POTS "sound" quality but that will have frustating delay due to TCP overhead.