| [Fixed] WISP latency causing poor voip call quality Please pardon my technical inexperience up front. I am attempting to educate myself.
I had a WISP install a 5/1Mbps internet connection to a customer site in Las Vegas.
The connection was installed to support two IP phones supporting 4 concurrent calls.
VOIP provider is telling me that there is too much latency to support good call quality.
when I ping the phones from my PC, in Chicago, I get response somewhere between 80 and 90ms.
Is there any simple fix to improve the latency?
Thanks |
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| Run a test at speedtest.net and pingtest.net and post the results. |
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| Microsoft Windows XP [Version 5.1.2600]
(C) Copyright 1985-2001 Microsoft Corp.
C:\Documents and Settings\Administrator>ping 64.250.228.113
Pinging 64.250.228.113 with 32 bytes of data:
Reply from 64.250.228.113: bytes=32 time=97ms TTL=47
Reply from 64.250.228.113: bytes=32 time=89ms TTL=47
Reply from 64.250.228.113: bytes=32 time=96ms TTL=47
Reply from 64.250.228.113: bytes=32 time=89ms TTL=47
Ping statistics for 64.250.228.113:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 89ms, Maximum = 97ms, Average = 92ms
I am not at the location so I cannot do a speed test |
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1 edit | most WISP have 80-90ping which really isn't that much of a delay and should work fine with VoIP.
My guess is you need more upload. 1mb is really 120~kb/s split 4 ways is only 30kb/s which may not be enough for your VoIP quality setting.
*that's assuming nothing else is running and your getting full speed.
/edit I could be wrong I don't use VoIP :/ »techtips.salon.com/much-bandwidt···127.html
"Depending on the protocol used, each concurrent call requires a bandwidth of between 30Kbps to 80Kbps."
" A low-end 2Mbps download and 512Kbps upload broadband connection should be enough for two or three concurrent calls" |
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| reply to palock34
4x 64kbit voip streams should easily fit into the 1mbit upload.
I would ask if the WISP is using TDMA. If not, then voip probably wouldnt work over the connection when the tower is under a small amount of load and I would suggest giving up now.
If they do use TDMA then you will want to look into your jitter.
Linksys voip phones have an adjustable jitter buffer - i just set mine to "extremely high" and it can move "up only", rather than "up and down" and it works fine.
90ms isnt really a problem. 500ms+ will be noticable as a small delay when talking - like watching a live news reporter being interviewed by the studio host via satelite link. But the stream should still be constant and work fine if the jitter buffer is working. |
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jcremin
join:2009-12-22
Siren, WI
kudos:2 | reply to Org
said by Org:1mb is really 120~kb/s split 4 ways is only 30kb/s which may not be enough for your VoIP quality setting.
You are mixing up kilobits (kb) with kilobytes (kB). 1 megabit is 1024 kilobits, or 128 kilobytes. A VOIP call at most should be 64 kilobits or 8 kilobytes. 1 meg should theoretically support 16 simultaneous 64kb phone calls, but in reality wouldn't leave any headroom. Either way, a few simultaneous calls should be fine.  |
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