Media Gateway Control Protocol (MEGACO/H.248.1)

MEGACO is used to control a Media Gateway in a VoIP system. MEGACO can be Text or Binary (ASN.1) encoded.


Protocol dependencies

Example traffic

H.248 over SCTP [attachment:H.248decoded.gif decoded] by Ronnie Sahlbergs decoder in the 0.10.9-SVN-13213 build.


The MEGACO dissector works for TEXT encoding of the protocol if EOL is used as SEParator. Dissection of binary encoding has recently been added (2004-10-25) as a separate dissector, it now handles binary H248 ower M3UA and SCTP in case of SCTP "decode as" may have to be used as the TEXT encoding dissector may take precedence.

If TCP is used there may be issues with desegmentation; such traces would be valuable.

Preference Settings

Example capture file

XXX - Add a simple example capture file to the SampleCaptures page and link from here. Keep it short, it's also a good idea to gzip it to make it even smaller, as Ethereal can open gzipped files automatically.

Display Filter

A complete list of MEGACO display filter fields can be found in the [ display filter reference]

Capture Filter

You cannot directly filter MEGACO protocols while capturing. However, if you know the ["TCP"] or ["SCTP"] port used (see above), you can filter on that one.