ot: isps

[Oleg Goldshmidt]

Rafi Gordon <rafigordon at gmail.com> writes:

> I heard that some cellular companies installed a blocking mechansim
> for their intenet clients which is called DPI.  see:
> http://en.wikipedia.org/wiki/Dpi

And choose "Deep Packet Inspection" from the options... ;-)

> AFAIK, this DPI can block voip application like Skype. 

That's an on-going war, similar to the war between P2P applications
and DPI. It's not limited to cellular companies, of course.

> And indeed one of the main usages of the DPI is to block VOIP
> traffic for celleular mobile clients who use skype.

If I have a Wi-Fi-capable cell phone and install Skype on it, then
mobile provider is nowhere on the path to do DPI (except inside the
phone, but DPI would be too heavy for the HW).
 
If one uses Skype over GPRS then the cell phone company can do DPI, I
suppose. They do get paid for GPRS usage, but a lot of it may be flat
rate. In Israel free Wi-Fi is common enough so using GPRS does not
make much sense in the first place, but in other countries it may be
an option.

> I believe that the same is for skype on the desktop.

This is even more true for the traditional infrastructure providers -
Bezeq and Hot. Both companies provide phone services, and one normally
gets a package of phone and Internet (and cable TV, for Hot) from the
same provider. Therefore, both have an interest to block services like
Skype, and both, sitting on the data path, can employ DPI.

An ISP would presumably like to provide you their own VoIP service
(and charge you for it), so they may be interested in blocking
everybody else, using DPI or whatever. But that is true for any ISP,
not just for a mobile provider.

> I apprecaite if anybody who know about the status of DPI in
> cellullar companies in Israel will share his knowledge.

Heh-heh, anybody from Allot on the list? Care to spill any corporate
secrets? ;-)

-- 
Oleg Goldshmidt | pub at goldshmidt.org