Enterasys Networks X-PeditionTM manual Q931 Decoding, Reference Parameters

Understanding ISDN

Rx ISDN-BRI 1/0 03:13:47:676 Q921 UI p 0 sapi 63 tei 127 c/r 1

•+ 2nd line:

info:0F 00 00 06 FF

Tx ISDN-BRI 1/0 03:13:52:601 Q921 INFO p 0 nr 0 ns 0 sapi 0 tei 64 c/r0 info:08 00 7B 3A 07 32 38 30 30 35 35 35

Tx ISDN-BRI 1/0 03:13:52:556 Q921 SABME p 1 sapi 0 tei 64 c/r 0

Rx ISDN-BRI 1/0 03:13:52:661 Q921 RR p/f 0 nr 1 sapi 0 tei 64 c/r 0

Reference Parameters

UI - Unnumbered Information.

SABME - Set Asynchronous Balanced Mode Extender. c/r - Command/Response field bit.

SAPI - Service Access Point Identifier. TEI - Terminal Endpoint Identifier. Ua - Unnumbered acknowledgement. nr - Receive Sequence Number.

ns - Send Sequence Number. INFO - Q931 Information message.

RR- Receive Ready

Note: For a complete list of reference codes, see: http://www.atis.org/tg2k/

Q931 Decoding

At Q931 Layer 3, the XSR partially decodes Q931 messages as follows:

•On line 1 after the time stamp field, the call reference and message type displays.

•On line 2, the complete hexadecimal dump of the message is shown.

•On the following lines the IEs, if any, display as follows:

–Hexadecimal code of the IE

–Name of the IE

–Hexadecimal dump of the IE or further decoding

Refer to the following Q931 example:

–+ 1st line:

Tx ISDN-BRI 1/0 03:32:48:203 CallRef=7 SETUP

–+ 2nd line:

00 81 12 0E 08 01 07 05 04 02 88 90 18 01 81 6C 06 00

80 32 38 30 30 70 05 80 32 35 30 30

XSR User’s Guide 11-7