ISP blocks MSN, google Talk, Yahoo, AIM,,,etc

zillah · 29 Apr 2007 at 12:12

I am looking to understand how ISP can block some service like MSN messenger or google talk , or yahoo messenger .

Does ISP block port only (layer 4) ? because I am pretty sure it is not the IP address, because there is a workaround if it is the ip address.

Or Are a protocol and the corresponding ports being blocked ?

If it blocks layer 7 , what does it block exactly ? if they are services what does that mean ?

Regards

csmager · 29 Apr 2007 at 12:15

Which ISP does this?(!)

It's extremely hard to block - MSN can work over it's own ports, or over HTTP, or via a proxy.

zillah · 29 Apr 2007 at 12:19

Which ISP does this?(!)

Recently I travelled to dubai, the ISP here called Etisalat , we can open MSN , but we can not use voice chat, same thing with yahoo.

With yahoo we can use voice conferencing to chat, but we can not use call option that comes with yahoo messenger

csmager · 29 Apr 2007 at 12:28

How do you connect?

This happens when the correct ports aren't open - usually done by uPnP if you have a router, or they're just forwarded to you if you're connected by a router.

If that isn't the issue, then they're probably blocking those ports (only allowing http traffic). MSN's connection status page will tell you how you're connected.

moid · 29 Apr 2007 at 13:06

Try Meebo instead:

http://wwwm.meebo.com/

bigredshark · 29 Apr 2007 at 20:43

how is it done? I couldn't say for sure as there's plenty of ways of doing it depending how much you want to spend...the ultimate is

http://www.packeteer.com/products/packetshaper/10000isp.cfm

which will do deep L7 inspection at almost gigabit wire speed, these appliances can block almost anything effectively, they cost the earth however.

Al Vallario · 29 Apr 2007 at 21:52

I believe Etisalat use — or were at least considering using — a system called Guardian from the British company Bitek.

The exact mechanics of the system appear to be a mystery, but I assume it is a little more advanced than simple port or destination IP blocking.

bigredshark · 29 Apr 2007 at 21:55

Al Vallario said:
I believe Etisalat use — or were at least considering using — a system called Guardian from the British company Bitek.

The exact mechanics of the system appear to be a mystery, but I assume it is a little more advanced than simple port or destination IP blocking.

sounds like a more targetted version of the same thing, packeteer and allot (netenforcer) dominate the market but there are others and most do much the same, L7 deep inspection in the high end products...

AthlonTom · 29 Apr 2007 at 23:13

bigredshark said:
how is it done? I couldn't say for sure as there's plenty of ways of doing it depending how much you want to spend...the ultimate is

http://www.packeteer.com/products/packetshaper/10000isp.cfm

which will do deep L7 inspection at almost gigabit wire speed, these appliances can block almost anything effectively, they cost the earth however.

Cool - we do management software for them apparently, I might have a look at the one in the office