mast_info <address>[/<port>]


mast_info(1) listens on the chosen address and port and waits for an RTP packet to be recieved. It then displays all the information it can work out about the packet.

The port number should be an even number (RTCP reports are sent one port higher). If no port number is specified, then the default RTP port number (5004) is used.


njh@dobbie:~$ mast_info ff7e:0440:2001:0630:00d0:f001:9000:7e57
Receive address: ff7e:0440:2001:0630:00d0:f001:9000:7e57/5004

RTP Header
Payload type    : 14
Payload size    : 526 bytes
Sequence Number : 60390
Timestamp       : 3219875130
SSRC Identifier : beef7e57
Marker Bit      : Not Set

Payload Details
Mime Type       : audio/mpa
Cock Rate       : 90000 Hz

MPEG Audio Header
MPEG Version      : MPEG-1 (Layer 2)
Mode              : Stereo
Bitrate           : 160 kbps
Sample Rate       : 44100 Hz
Error Protection  : No
Padding           : No
Extension Bit     : No
Copyright         : No
Original          : Yes
Samples per frame : 1152
Bytes per frame   : 522


Written by Nicholas J. Humfrey, <>


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RTP Payload types:


Copyright © 2003-2007 Nicholas J Humfrey. Free use of this software is granted under the terms of the GNU General Public License (GPL)