I am testing several phones for an eventual 3cx deployment. The three phones I'm testing right now include: Cisco SPA 303, Yealink T20P, and a Yealink T48g (firmware 35.73.0.50).
I love the T48G. It's affordable, it's fast, I love the dss keys, the flexibility, the interface, I love it all. However, upon extensive testing I have definitively identified that it is adding on the order of 175ms delay on outbound audio.
I have two versions of 3cx running: one is hosted in Seattle through 3cxhost.com and the other is a local install on my LAN on one of my servers. I have the phones registered to both servers. In order to test latency I record finger snaps using Audacity and then I can quickly measure the distance between the sound waves and be very precise in my figures. Because latency is my biggest concern with this deployment, I have done extensive testing. My tests include extension to extension calling using the hosted server and the server on my LAN. While connected from extension to extension, I would mute one phone and would snap in the other recording both my finger snap and the sound on the other extension using an external microphone. My results were not impacted based on who called who first (ie ext 1 -> ext 2 vs ext 2 -> 1 didn't matter, which would have shocked me if it did). In the results below, I have obviously averaged because they weren't all EXACTLY the PRECISE same number of milliseconds, however if they were within 20 ms then I made them the same. Here are the results:
Hosted Server
SPA -> T20: 165ms
T20 -> SPA: 165ms
T48g -> T20: 165ms
T48g -> SPA: 165ms
T20 -> T48G: 340ms
SPA -> T48g: 340ms
LAN Server
SPA -> T20: 45ms
T20 -> SPA: 45ms
T48g -> T20: 45ms
T48g -> SPA: 45ms
T20 -> T48G: 220ms
SPA -> T48g: 220ms
This is using the G711 on the t48. I tried some of the other codecs and didn't have any results that differed substantially from the above. At least, I think I tried others. I moved some of them up on the list in the phone settings, and then eventually removed all codecs but the one I wanted to try, and so I assume that forces it to use the remaining codec.
Conclusion/Problem/Question: Why is the T48g adding 175ms to outbound audio?????? I really like this phone but I'm trying to shave down latency and working my butt off to do that and the T48 is kicking me in the teeth!
Thanks,
Tyson
I love the T48G. It's affordable, it's fast, I love the dss keys, the flexibility, the interface, I love it all. However, upon extensive testing I have definitively identified that it is adding on the order of 175ms delay on outbound audio.
I have two versions of 3cx running: one is hosted in Seattle through 3cxhost.com and the other is a local install on my LAN on one of my servers. I have the phones registered to both servers. In order to test latency I record finger snaps using Audacity and then I can quickly measure the distance between the sound waves and be very precise in my figures. Because latency is my biggest concern with this deployment, I have done extensive testing. My tests include extension to extension calling using the hosted server and the server on my LAN. While connected from extension to extension, I would mute one phone and would snap in the other recording both my finger snap and the sound on the other extension using an external microphone. My results were not impacted based on who called who first (ie ext 1 -> ext 2 vs ext 2 -> 1 didn't matter, which would have shocked me if it did). In the results below, I have obviously averaged because they weren't all EXACTLY the PRECISE same number of milliseconds, however if they were within 20 ms then I made them the same. Here are the results:
Hosted Server
SPA -> T20: 165ms
T20 -> SPA: 165ms
T48g -> T20: 165ms
T48g -> SPA: 165ms
T20 -> T48G: 340ms
SPA -> T48g: 340ms
LAN Server
SPA -> T20: 45ms
T20 -> SPA: 45ms
T48g -> T20: 45ms
T48g -> SPA: 45ms
T20 -> T48G: 220ms
SPA -> T48g: 220ms
This is using the G711 on the t48. I tried some of the other codecs and didn't have any results that differed substantially from the above. At least, I think I tried others. I moved some of them up on the list in the phone settings, and then eventually removed all codecs but the one I wanted to try, and so I assume that forces it to use the remaining codec.
Conclusion/Problem/Question: Why is the T48g adding 175ms to outbound audio?????? I really like this phone but I'm trying to shave down latency and working my butt off to do that and the T48 is kicking me in the teeth!
Thanks,
Tyson