Re: SS7oIP rate generated

ali,

ali ovaisi wrote:                               (Fri, 22 Jun 2007 11:20:28)
> 
>    Dear Sigtran fellows
> 
>    I am a student and doing a project related to SS7oIP

Then I assume that you might actually want to learn something instead of
just being told.

>    To  accomplish  my project I have to achieve the task that What is the
>    SS7oIP  rate  generated by each of the following protocols for a given
>    VoIP traffic.

Then I also assume that you do not simply want to be told the answer.

>    M3UA

M3UA carries in it MTP3 messages (see the DATA message description in section
3 of RFC 4666).  MTP3 messages correspond to regular PSTN (not VoIP) telephone
calls and are either ISUP messages (call control) or TCAP/SCCP messages (INAP
queries, LNP dips, location services).  To understand ISUP messaging requires
understanding how telephone switches communicate with each other for making
telephone calls in the network.  From purely a protocol perspecfic, examples
can be found in any good book written on telecommunications that has at least
a section on SS7.

You will see three books (that are old enough they should be at a library)
mentioned here:

 http://www.openss7.org/faq13.html
 
There is a tutorial on SS7 that many people recommend here:

 http://www.pt.com/tutorials/ss7/

There are better web resources: Google is your friend.

What you need to do is to take the message format for a typical ISUP call flow
IAM, ACM, ANM/CPG, REL, and RLC message and count up the number of bytes for
each and then add in the overhead of the M3UA DATA message.  The IAM is
difficult as it can contain many optional parameters that depend upon the
specific country of operation, the features associated with the call, and the
position in the switching hierarchy.  IAM message use to be about 45 bytes
in Canada back when I used to do network engineering, but LNP and other things
have probably raised that to about 60 bytes.  The other mesages do no normally
carry many optional parameters except the REL.  Note that unsuccessful calls
also use almost as many messages.  All in all the order-of-manitude rule of
thumb used to be to estimate that a call takes 5 messages and that the average
length of the messages is 35 bytes (I can't remember whether that included the
FSN/BSN and RL, I'm pretty sure it did) so about 175 bytes per call.

If you need refined numbers you would have to actually capture SS7 or M3UA
traffic from a real network and analyze it statistically or using a traffic
model.  Modelling of traffic in a telephone network is an entire field of
study.

>    M2UA

M2UA carries a little more of the SS7 message in the MAUP data (it includes
FSN/BSN whereas M3UA does not).  FSN/BSN are 2 bytes for each message.
See section 3 in RFC 3331.


>    M2PA

M2PA does not carry FSN/BSN from the SS7 message, but adds its own in the User
Data message whose format is given in section 2.3.1 of RFC 4165.

>    Need your help and guidance
>    hope to get reply soon

If you need more guidance, I suggest that you consult with the people at
your learning institution that assigned the project to you.

--brian

-- 
Brian F. G. Bidulock
[email protected]
http://www.openss7.org/