Skype bandwidth Usage

AnomalyNexus said:
No, he is right. If one guy in tokyo is phoning another guy in tokyo both with 100mbit lines then it will use a hell of a lot more than on an SA line.
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Why will it use more bandwidth? To transfer audio and video over a 4mb line and a 100mbit line, should be the same amount of bandwidth?

I can understand that maybe 56k is downgraded video and audio quality resulting in less bandwidth being transferred, but 2 decent internet connections should have the same amount of data transferred.
 
AnomalyNexus said:
No, he is right. If one guy in tokyo is phoning another guy in tokyo both with 100mbit lines then it will use a hell of a lot more than on an SA line.
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Kuk. The maximum bandwidth required for Telco grade voice is 64kb/s. VoIP uses way more conservative codecs to achieve a much lower bit rate. Just because there is a 100mb/s link does not mean the application is going to use it as it is senseless to do so.
 
Also keep in mind that Skype uses a peer to peer topology, meaning someone else's traffic may be getting routed through your connection. This tends to up bandwidth usage considerably when you have a nice and fast, idling internet connection.
 
Messugga said:
Also keep in mind that Skype uses a peer to peer topology, meaning someone else's traffic may be getting routed through your connection. This tends to up bandwidth usage considerably when you have a nice and fast, idling internet connection.
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This is definitely something worth noting...

Does Skype have the option of disabling that kind of p2p relaying traffic?
 
ponder said:
Kuk. The maximum bandwidth required for Telco grade voice is 64kb/s.
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You are awfully quick to call "Kuk" on this. :rolleyes: We are talking about bandwidth usage here, not codec bitrate.

Here is a graph of a test skype call I just made to Skype's call testing service (echo123). The graph is scaled to 128kb/s, i.e. twice what you said is the max. It's consistently above 64kb/s. Feel free to test that yourself (I'm using unshaped IS bw).

ponder said:
VoIP uses way more conservative codecs to achieve a much lower bit rate.
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To achieve a lower bit rate the codec would have to be more aggressive.

ponder said:
Just because there is a 100mb/s link does not mean the application is going to use it as it is senseless to do so.
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ToAsTeD said:
Why will it use more bandwidth? To transfer audio and video over a 4mb line and a 100mbit line, should be the same amount of bandwidth?
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I see I should have said "two 4mb lines in tokyo" to avoid sidetracking people on the 100mbit thing. Skype contains multiple codecs (SVOPC and SILK mainly) and picks a different one depending on how it evaluates the lines, it'll pick a different one. Which is what fbman said:
fbman said:
The amount of bandwidth skype uses depends on your internet connection and the person you are calling. Then it chooses the appropriate quality settings
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And thats why I decided to back him up.;) Didn't quite expect ppl to come out guns blazing for that.:wtf:

The 100mbit tokyo lines was an example of a situation where there is no shaping, low latency and "unlimited" bw. In that situation skype is guaranteed to use its highest call quality setting. Here in SA on a shaped to death line this is not necessarily so. Thus bw usage are likely to differ.

Pada said:
Does Skype have the option of disabling that kind of p2p relaying traffic?
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No, it doesn't cause Skype Co wants people's PCs to act as supernodes as it improves the overall quality of the skype network. You can avoid it by remaining behind a NAT.
 
AnomalyNexus said:
Here is a graph of a test skype call I just made to Skype's call testing service (echo123). The graph is scaled to 128kb/s, i.e. twice what you said is the max. It's consistently above 64kb/s. Feel free to test that yourself (I'm using unshaped IS bw).
Click to expand...

Just did the same test to echo123 and it peaked at 7.8kB/s and averaged about 5-6kB/s which is below 64kb/s and more like an average of 40-48kb/s. This is on a unshaped Cybersmart account.
 
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ponder said:
Just did the same test to echo123 and it peaked at 7.8kB/s and averaged about 5-6kB/s which is below 64kb/s and more like an average of 40-48kb/s.
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Yes, I know about bits & bytes.;)

If you really think 64kbps represents a limit, then how would you explain this then: (from the hellkom link you posted)
highest observed usage (9.5KB/s)
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I just don't see why the codec bitrate should represent a limit on the connection's bw usage. Things like packet loss protection, overheads, encryption, double sending of packets could easily push it much higher especially on high latency links like SA-London.

Sure I've seen skype stay (more or less) within the range you specified, but that was always on a shaped saix connection. I've also seen it stay far higher (10KB/s+ consistently) during entire conversations (like today).

ponder said:
This is on a unshaped Cybersmart account.
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afaik those are SAIX accounts though, which could explain the difference. I've seen low bw usage on saix, but I always concluded that its because it was a shaped saix a/c.
 
AnomalyNexus said:
I see I should have said "two 4mb lines in tokyo" to avoid sidetracking people on the 100mbit thing. Skype contains multiple codecs (SVOPC and SILK mainly) and picks a different one depending on how it evaluates the lines, it'll pick a different one.
The 100mbit tokyo lines was an example of a situation where there is no shaping, low latency and "unlimited" bw. In that situation skype is guaranteed to use its highest call quality setting. Here in SA on a shaped to death line this is not necessarily so. Thus bw usage are likely to differ.
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Thanks for the explantation :D
 
Hey Guys

Gents, thought I would paste in here for those of you who are interested. Where we now not worry about our Skype usage :)

Here is a special on behalf of PLuGG (Internet Solutions) towards their sponsored team (Bravado) towards the community!

Bravado Gaming, on behalf of their sponsor, PLuGG (a Division of Internet Solutions), are running a special on their ADSL accounts. These accounts come at the special low price of R22/GB, one of the cheapest prices for international internet bandwidth in South Africa!

This special is valid forever and is a month-to-month contract, meaning you can cancel the subscription at any time and is available for all PluGG packages: 1, 3, 5, 10, 20, 30GB which can be topped up at any time for R22/GB. However, only the first 100 subscribers will be eligible for this special, so don’t miss out. Additionally, when your account runs out you will receive the same amount of data in local bandwidth. So for example if you buy a 5GB account and it gets capped, you will then get 5GB worth of local bandwidth.

All you have to do is e-mail [email protected] and include which package you would like, your name and alias. Soon after you will be sent an e-mail from PLuGG/Internet Solutions with a voucher and instructions on how to redeem it. (All instructions are included in the email) You can redeem it at any time and you will only be billed (via debit order only) once you have redeemed the voucher. A reminder that this offer only lasts for this week.

Any questions can be forwarded to the email specified. We are doing this for you, the community.

Please note: The special is not listed on the IS or PLuGG website, (www.plugg.co.za) as it is a once of special to the gaming community through Bravado.

Thanking you!
Bravado
Reply With Quote
 
Thanks Globetrotter & AnomalyNexus for the info. It's good to know that NAT / a simple registry entry can prevent Skype from acting as a SuperNode.

alphaboy07: that's a bit off topic, but I must say that its a quite low price :)
Rather prevent Skype from using unnecessary bandwidth than to get more cap...
 
ponder said:
Most definitely not, they provision their own bandwidth via AS6453 which is TATA http://www.as6453.net/
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I wouldn't know. I guessed SAIX based on the fact that their news server redirects to the SAIX news server, which only allows saix connections. I guess they are running a hybrid system of sorts then.
Code: 
C:\Documents and Settings\AN>ping news.cybersmart.co.za

Pinging news.cybersmart.co.za [196.43.2.61] with 32 bytes of data:

Control-C
^C
C:\Documents and Settings\AN>ping news.saix.net

Pinging news.saix.net [196.43.2.61] with 32 bytes of data:

Control-C
^C
C:\Documents and Settings\AN>
 
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