voip: skype, vbuzzer, freephoneline, etc

Chan Chung Hang Christopher christopher.chan at bradbury.edu.hk
Mon Jul 12 11:02:03 UTC 2010

Thufir wrote:
> On Mon, 12 Jul 2010 11:04:12 +0800, Christopher Chan wrote:
>>> If my connection were better, then SIP would be great, but it's not an
>>> option, unfortunately.
>> What is your connection like?
> Technically, it meets VoIP requirements as per callcentric and their 
> recommended website for testing that:  http://myvoipspeed.visualware.com/, 
> which came back with:
> visaulware results:
> Test Type: Voice over IP
> Downstream Jitter: 3.49ms
> Downstream Loss: 0 %
> Downstream Packet Order: 100 %
> Upstream Jitter: 6.7ms
> Upstream Loss: 0 %
> Upstream Packet Order: 100 %
> Packet Discards: 0 %
> MOS Score: 3.9
> Glossary of Results 
> I use a "slow" or "lite" speed service with a cable modem.  I'm still 
> working with callcentric tech support, who are quite helpful, but I'm 
> dubious as to the outcome.

So long as you get 256kbit/256kbit speeds you should be okay. What you 
really need is to ensure that sip packets get priority...

> I had a PVR from the cable company but it would periodically basically 
> stop working, the image would be completely pixelated.  A technician 
> inferred that there was a splitter somewhere because he wasn't able to 
> test our line, but he did have someone come out and replace parts outside 
> the residence, however, those parts turned out not to be broken.  I 
> figure that the wiring in the house just wasn't done properly.
> I might upgrade the service to at least test whether that helps.

Does that happen when there is high humidity or something? The school 
here used to see the Internet line speed hit rock bottom whenever it 
rained. Now that the school is on fibre, we have not had any such problem.

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