Wireless Intenet Service - Problems with choppy connection

Posts: 16 · Vonage Forum Associate Joined: Jul 20, 2005 Posts: 16

I live out in the sticks where the only broadband ISP is a dedicated wireless (line of sight) connection. My voice quality is very poor, with choppy reception on the download side. Apparently it sounds fine on the upstream side. Anyone with knowledge on how to tweak the system to correct this problem would be much appreciated.

Posts: 646 · Posted: Thu Jul 21, 2005 1:36 pm Post subject:

Go to www.testyourvoip.com , do a call to Boston, and post your detailed results here, for the incoming and outgoing directions.

Posts: 16 · Vonage Forum Associate Joined: Jul 20, 2005 Posts: 16

Test Details
The information below explains why your call quality score (MOS) was less than perfect.

Find the results that you want more quickly...
Jump to: Media Quality Signaling Quality

MOS Analysis from You TO Boston

Media Quality MOS 4.0 / 5.0
(Best with G.711 is 4.4)

Degradation Sources
Codec 0.57 55.7%
Latency 0.18 17.6%
Packet Discards 0.19 18.5%
Packet Loss 0.08 7.9%

Codec G.711 (PCM at 64kbps,
20ms RTP payload,
80kbps IP BW)
Round-Trip
Latency 387 ms
Packet Discards 0.9%
Packet Loss 0.4%
Loss Periods Min: 20 ms
Avg: 20 ms
Max: 80 ms
Burst Loss

Jitter Min: 0 ms
Avg: 4 ms
Max: 46 ms

Signaling Quality Post-Dial Delay 60 ms
Call Setup Time 70 ms
Media Delay 140 ms
MOS Analysis FROM Boston To You

Media Quality MOS 3.6 / 5.0
(Best with G.711 is 4.4)

Degradation Sources
Codec 0.57 41.6%
Latency 0.21 15.2%
Packet Discards 0.50 36.3%
Packet Loss 0.09 6.8%

Codec G.711 (PCM at 64kbps,
20ms RTP payload,
80kbps IP BW)
Round-Trip
Latency 387 ms
Packet Discards 2.1%
Packet Loss 0.4%
Loss Periods Min: 20 ms
Avg: 60 ms
Max: 140 ms
Burst Loss

Jitter Min: 0 ms
Avg: 18 ms
Max: 340 ms

Signaling Quality Post-Pickup Delay 56 ms
Call Setup Time 67 ms
Media Delay 87 ms

Posts: 646 · Posted: Thu Jul 21, 2005 2:14 pm Post subject:

You're definitely getting a lot of jitter in the downstream direction. Try contacting your ISP and see if they can do anything about it... they might be able to analyze your connection and see if there's something wrong with the signal.

Does anyone know if Vonage is able to change the size of the jitter buffer? That seems like it could help a lot of quality problems people are having, at the cost of extra latency.

Posts: 646 · Posted: Thu Jul 21, 2005 2:29 pm Post subject:

Here's an interesting article I just found:
http://blog.tomevslin.com/2005/04/living_with_jit.html

He claims that the PAP2 is much better than the old Motorola at dealing with jitter. I would hope that the RT31P2 and others work the same as the PAP2 in that regard, but I'm not sure.

Which Vonage box do you have?

Posts: 2257 · Posted: Thu Jul 21, 2005 2:34 pm Post subject:

paul248 wrote:

Here's an interesting article I just found:
http://blog.tomevslin.com/2005/04/living_with_jit.html

Two points of interest regarding that blogger:

1) I believe he is a Vonage Forum Member.
2) That is an excellent site Smile

Posts: 16 · Vonage Forum Associate Joined: Jul 20, 2005 Posts: 16

I have the RT31P2.
I am emailing my ISP connection to see what they can do on their end, and will check out the article... thanks

Posts: 16 · Vonage Forum Associate Joined: Jul 20, 2005 Posts: 16

Excellent reference !! Sounds like the exact problem I am experiencing. Would lead me to believe that the RT31P2 box I received with my new service does not have as large a buffer.

Two quick follow up questions:

How can I find out for sure (without shelling out $60 and trip to Circuit City) if the buffer size is better on the PAP2 vs the RT31P2?

and (more interesting technical question)

Will increasing my download bandwidth (currently about 400 kbps and upgradable to lots more for additional cost) overcome the jitter problem ??

Posts: 13 · Vonage Forum Associate Joined: Mar 03, 2005 Posts: 13

I AM a Vonage forum member and a fan of dconner who does such an excellent job here. Still having excellent experience on marginal IP with my two PAP2s and also with one we installed on DSL in a developing country.

I think - but don't know - that the PAP2 may do such a good job because it is relatively stupid. It just does Voip; it does not have router functionality built in like the Motorola ATA or RT31P2. That means it MUST be behind a router but that's the way I'm configured anyway.

Good luck.

Tom
blog.tomevslin.com

Posts: 646 · Posted: Thu Jul 21, 2005 5:26 pm Post subject:

My guess is that the PAP2 and RT31P2 use the same Voip algorithms, but I could be wrong. The only evidence I have to back it up is that the RT31P2's current Voice version is 3.1.3, which is the same as the firmware version on the PAP2.