Subject: N. Greene September 23 memo comparing MGCP and MEGACO

From: Mike Coffee <[email-masked]>
Date: Wed, 20 Oct 1999 08:56:45 -0400

Hello, Nancy,

I just saw an e-mail saying you had posted an e-mail on September 23 that
contrasted MGCP and MEGACO.  I should probably know the answer to this
question, but will  you tell me how to access that posting?  Are they
archieved somewhere?

Thanks,
Mike Coffee
Commetrex Corp.
[email-masked]
http://www.commetrex.com

---

From: Neta Zmora <[email-masked]>
Date: Wed, 20 Oct 1999 17:04:27 +0200

Mike,

Since I posted the mail you're referring to, and since Nancy is probably
very busy in Redbank, I've pasted her original mail below.
The Megaco mailing list is archived at:
http://standards.nortelnetworks.com/archives/megaco.html
In general, each WG posts its archive location at its charter page (e.g.
http://www.ietf.org/html.charters/megaco-charter.html for MEGACO).

Neta

---------------------------------------------------------------------------
Here is my summary of the differences, as well as a pdf file with a table
comparing the two. The table is something I produced in March, 1999 when we
were comparing predecessors to the Megaco protocol. I have updated it to
compare Megaco and MGCP.

Please send me any comments!

 <<MegacovsMGCPv1.pdf>>
References:
[1] F. Cuervo, B. Hill, N. Greene, C. Huitema, A. Rayhan, B. Rosen, J.
Segers, "Media Gateway control protocol (Megaco/H.248)", Working Document
of
the IETF Megaco WG, <draft-ietf-megaco-protocol-04.txt> (or
ftp://standards.nortelnetworks.com/megaco/docs/latest/megaco-h248_protocol.
p
df  ), Sept 1999
[2] M. Arango, A. Dugan, I. Elliott, C. Huitema, S. Pickett, "MGCP 0.1",
<draft-huitema-megaco-mgcp-v0r1-05.txt>, May 1999
[3] M. Arango, A. Dugan, I. Elliott, C. Huitema, S. Pickett, "MGCP 1.0",
<draft-huitema-megaco-mgcp-v1-02.txt>, August 1999

Note that <draft-ietf-megaco-protocol-04.txt> will be available later this
week - it will be a full text-only version of the Megaco/H.248 protocol. It
will be identical to the pdf file already available at
ftp://standards.nortelnetworks.com/megaco/docs/latest/megaco-h248_protocol.
p
df

I have also put the comparison tables attached here on the above ftp site.

Main Differences between Megaco/H.248 and MGCP
---------------------------------------------------------------------------
1) transactions
- Megaco/H.248 uses transactions to group together commands. Command
responses and errors are clearly marked in the transaction reply.

- MGCP uses command embedding, and it is not easy to find the individual
responses to embedded commands.

2) multimedia
- Megaco/H.248 is multimedia ready - it has a defined way to set mixing
parameters for video, audio - default is audio mixing of all terminations
in
a context.
- although MGCP uses sdp, it does not have any capability to set mixing
parameters for video, for example. Thus it is not as multimedia ready as
Megaco/H.248.

3) moving a termination/endpoint from one "call" to another
- in Megaco/H.248 you use Move to move a termination from one context to
another. Useful for call waiting, 3-way calls.

- MGCP v0r1-05 does not have a Move command - the newest MGCP v1 does have
a
Move command.

4)  Packages
- An Internet-Draft of Megaco/H.248 generic packages for lineside and
trunking will be published in a week. They draw heavily from MGCP, but
should be clearer to use and more complete. They will be published
separately from the Megaco/H.248 base protocol, with registration to be
done
through IANA, and with version numbers. (In the IETF, they will be in
separater RFCs, and in the ITU-T SG16, they will be annexes to H.248). New
packages not in MGCP are also being defined - i.e. for R2, for IP Phone, as
well as a standard way to register new packages and updates to existing
packages.

- MGCP packages are bundled into the MGCP document. Not easy to evolve
them,
nor update them, nor no standardized way to register them.

5) Call Model
- Megaco/H.248 has a more general call model than MGCP - thus more
efficient for TDM to TDM calls, TDM to ATM calls, etc., as well as still
working well for TDM to IP calls.

6) Multiplexing
- the Megaco/H.248 protocol supports multiplexing, while MGCP does not.

7) Authentication Header
- the Megaco/H.248 protocol includes an authentication header that
providessecurity when IPSEC is not available.

- MGCP does not have this.

8) failover
- Megaco/H.248 allows the MGC to provide a new MGC the MG should
communicate
with in the ServiceChange command.

- MGCP does allow the MGC to send a new MGC to contact to the MG - it is
piggybacked on certain commands.

Nancy
--------------------------------------------------------------------------
Nancy M. Greene
Internet & Service Provider Networks, Nortel Networks
T:514-271-7221 (internal:ESN853-1077) E:[email-masked]

Mike Coffee <[email-masked]> on 20/10/99 02:56:45 PM

Please respond to Mike Coffee <[email-masked]>

To:   [email-masked]
cc:    (bcc: Neta Zmora)
Subject:  N. Greene September 23 memo comparing MGCP and MEGACO

Hello, Nancy,

Thanks,
Mike Coffee
Commetrex Corp.
[email-masked]
http://www.commetrex.com