Skype over Iburst

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ekkesa

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Can some please clarify this.

I'm trying to use skype, but the connection is extremely crappy. It used to work 100%, and nothing has changed on my side.

My setup is as follows:

IBurst with external antenna (Not capped yet)
Downloads @ 100K - 120K
Speed test on Iburst: All the items show green
utTraceStar: -66
Iburst Dashboard: 99% signal strength
Tower: Groenkloof (Pta) <-- Line of sight (about 1.5km)

As you can see form the above information my connection seems to be running almost at full capacity when sending & receiving traffic.

But on the contrary, the skype calls have echoes and sometimes dips away. Now I believe this is due to latency, but all test shows that my latency is not that high.

Is this maybe related to the strict port shaping IBurst have implemented?

Anybody else having such problems?

PS: I posted this on the Iburst blog aswell, for what it is worth... <-- the blog is giving XML errors as expected from IBurst, will keep trying...
 
Last edited:
your speed seems slow. if you're that close you should be getting more like 1000kbps. Maybe there's something wrong with your PC software set up. Microsoft gets worse and worse with time as you get so many updates. Also do you use a PCMCIA card? Some PCs have a software bug with this compared to a USB or dektop modem.
 
PS> we've got SKype and Telio VOIP service connected to PCMCIA and desktop modem now for over a year and its perfect except sometimes skype can be rubbish because there's no quality guarantee.
 
prc66 said:
your speed seems slow. if you're that close you should be getting more like 1000kbps. Maybe there's something wrong with your PC software set up. Microsoft gets worse and worse with time as you get so many updates. Also do you use a PCMCIA card? Some PCs have a software bug with this compared to a USB or dektop modem.
Click to expand...

When he said 100-120K, that is 100KB/s to 120KB/s which is over 1000kb ;)
 
I just took it as 100kilobits would be 100k with a small k :p

Edit* HA 900th Post :D
 
GreatBigMouth said:
Isn't 100K referred to as 100kilobits? :confused:
Click to expand...

Hi,

My understanding is the following:

1 bit
8bits in in Byte
1024kilobits in a Megabit

Thus:

Iburst = 1 Megabit per second
Thus to convert this to the Kilobytes to get Max throughput.

1024kb/8 = 128KB

So theoretically you can get a Max of 128K on IBurst :D

This is my understanding of it, please correct me if I'm wrong..
 
Last edited:
prc66 said:
Maybe there's something wrong with your PC software set up. Microsoft gets worse and worse with time as you get so many updates. Also do you use a PCMCIA card? Some PCs have a software bug with this compared to a USB or dektop modem.
Click to expand...

Hi,

PC Software setup is 100% got 4 machines running on a network (3 Windows, 1 Linux) and I tried it on all the machines and got the same result. Thus eliminating a software setup problem. Also check the router and all the settings are intact. I rebooted the Router & Modem for good measure aswell.

I'm using a Desktop Modem connected via Ethernet to a Linksys WRT54G DD-WRT router.
 
ekkesa said:
Can some please clarify this.

I'm trying to use skype, but the connection is extremely crappy. It used to work 100%, and nothing has changed on my side.

My setup is as follows:

IBurst with external antenna (Not capped yet)
Downloads @ 100K - 120K
Speed test on Iburst: All the items show green
utTraceStar: -66
Iburst Dashboard: 99% signal strength
Tower: Groenkloof (Pta) <-- Line of sight (about 1.5km)

As you can see form the above information my connection seems to be running almost at full capacity when sending & receiving traffic.

But on the contrary, the skype calls have echoes and sometimes dips away. Now I believe this is due to latency, but all test shows that my latency is not that high.

Is this maybe related to the strict port shaping IBurst have implemented?

Anybody else having such problems?

PS: I posted this on the Iburst blog aswell, for what it is worth... <-- the blog is giving XML errors as expected from IBurst, will keep trying...
Click to expand...

Lower your MTU to 1324, disable the use of port 80 & 443 in the Skype connection settings and ensure incoming connections to your pc on port 42652 is properly forwarded if you are making use of a router or just use Lowrate VoiP, it delivers superior voice quality connection and is far more cost effective than Skype and it's hype...
 
Last edited:
ekkesa said:
Hi,

My understanding is the following:

1 bit
8bits in in Byte
1024kilobits in a Megabit

Thus:

Iburst = 1 Megabit per second
Thus to convert this to the Kilobytes to get Max throughput.

1024kb/8 = 128KB

So theoretically you can get a Max of 128K on IBurst :D

This is my understanding of it, please correct me if I'm wrong..
Click to expand...

iBurst can sometimes go faster than 1024kb/s. I've seen it with my own eyes. Try logging in at 3am in the morning, you'll get 1.1mb/s or even a little faster. :cool:
 
who.is.michael said:
Lower your MTU to 1324, disable the use of port 80 & 443 in the Skype connection settings and ensure incoming connections to your pc on port 42652 is properly forwarded if you are making us of a router
Click to expand...

If this is a n00b question forgive me, but please explain why these settings will increase the performance of skype.

Also why port 42652? Skype uses random ports, doesn't it?

Thankz
 
Skype connection settings

Skype connection settings:

Skype uses random outgoing ports however incoming ports are restricted to:
80, 443 & (42652 – can be altered). It is best to stay clear of port 80 as it is used for browsing and monitored by iBurst, also it is best to stay well clear of the port ranges which iBurst restricts, as per the feeble excuse on their site - pasted below;

"Due to excessive DoS attacks and worm traffic, the following ports will be restricted: tcp 445, 135, 139, 1433, 1434; udp 1433, 1434. Furthermore, peer to peer traffic is shaped on most iBurst packages. SMTP relaying on port TCP 25 is restricted to authorised SMTP relays only."

Therefore usage of port ranges above 2000 is advised (check to see if any other application is using the port you have selected by visiting this site https://www.grc.com/PortDataHelp.htm), Low Rate VoIP uses port 3830, and you can alter Skype’s incoming port from 42652 to any other of your choice above the previously mentioned restricted ranges, just remember to alter your firewall settings for the newly selected port. Also, if you have a firewall which supports SIP (Session Initiation Protocol) ALG (Application Level Gateway) typically on port 5060 either TCP or UDP, enable it and use that port.

As for the MTU, in short - the bigger the size of your MTU the larger the packet size and the greater the latency becomes and possible fragmentation could occur when the MTU is set above the recommended size of 1352, however I have had success with a MTU setting of 1492, which is ideal for fast web browsing and downloads.
Although the increase in MTU size enables better browsing, etc. - it negatively affects gaming, VPN and other applications that require quicker response times (lower latency), which a lower MTU setting facilitates. I use 1324, but you could set it well below this but have a look at this post http://mybroadband.co.za/vb/showthread.php?t=79653 on how to test for the most appropriate MTU setting to establish the lowest possible latency for your connection.

The MTU size of 1324 is a good compromise for most applications and still facilitates good throughput for downloads and smooth browsing.

I would still advise the use of LR VoIP, instead of using Skype.

Let me know of the outcome.

Regards

M

Some further reading on MTU settings - http://en.wikipedia.org/wiki/Maximum_transmission_unit

ambo said:
Default MTU for Ethernet is in fact 1500 - the MTU of 1492 is the default MTU of PPPoE connections. A PPPoE connection (in very simple terms) is one type of connection packaged inside another - a very basic type of VPN if you will. Now some of the 1500 bytes of the Ethernet packet is consumed for PPPoE overheads. PPPoE is used for ADSL as well - but most of the MTU issues are handled internally by the modern router-modem combos.

Reason for using PPPoE and not straight Ethernet (particularly in ZA) is that the ISPs want a connection inside a controlled pipe so that they can watch you with their big "i'm gonna cap you" camera :p

iBurst obviously also uses PPPoE for their connections - difference being their physical transmission layer being air. Now experience has shown that sending a full 1492 packet + PPPoE overheads has produced a large number of packets that have 1 or 2 erroneous bits if data and are thus dumped. This dumping results in the considerable speed degredation. The MTU that is suggested by iBurst is the best compromise between error prevention and transport efficiency.

As far as i know... :D
Click to expand...
 
Last edited:
who.is.michael said:
Skype connection settings:

Skype uses random outgoing ports however incoming ports are restricted to:
80, 443 & (42652 – can be altered). It is best to stay clear of port 80 as it is used for browsing and monitored by iBurst, also it is best to stay well clear of the port ranges which iBurst restricts, as per the feeble excuse on their site - pasted below;

"Due to excessive DoS attacks and worm traffic, the following ports will be restricted: tcp 445, 135, 139, 1433, 1434; udp 1433, 1434. Furthermore, peer to peer traffic is shaped on most iBurst packages. SMTP relaying on port TCP 25 is restricted to authorised SMTP relays only."

Therefore usage of port ranges above 2000 is advised (check to see if any other application is using the port you have selected by visiting this site https://www.grc.com/PortDataHelp.htm), Low Rate VoIP uses port 3830, and you can alter Skype’s incoming port from 42652 to any other of your choice above the previously mentioned restricted ranges, just remember to alter your firewall settings for the new port. Also if you have a firewall which supports SIP (Session Initiation Protocol) ALG (Application Level Gateway) typically on port 5060 either TCP or UDP, enable it.

As for the MTU, in short - the bigger the size of your MTU the larger the packet size and the greater the latency becomes and possible fragmentation. This enables better browsing however is detrimental to gaming and other applications that require quicker response times, with a lower MTU setting. I use 1324, but you could set it well below this but have a look at this post http://mybroadband.co.za/vb/showthread.php?t=79653 on how to test for the most appropriate MTU setting to establish the lowest possible latency for your connection.

I would still advise the use of LR VoIP, instead of using Skype.

Let me know of the outcome.

Regards

M
Click to expand...

Thankz for the extensive reply.. Really much appreciated. :)

Will try these settings and let you know of the outcome...


..... now off to ping some stuff :D
 
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