WCS LAPD Server over T1 E1

Overview

LAPD Server is GL's WCS based server module which runs as a special task under the GL Server. The WCS LAPD Server provides Layer 3 LAPD protocol services over GL's T1 E1 boards. It permits to create multiple LAPD links of various bandwidths (time-slots, sub-channels) and provides UDP interface to the client applications for generating & receiving LAPD payload over these created LAPD streams.

LAPD is the protocol used on ISDN's (Integrated Services Digital Network) D channel. Link Access Procedures on the D channel (LAPD), specified in ITU-T Q.920 and ITU-T Q.921, is the second layer protocol on the ISDN protocol stack in the D channel. The LAPD Server provides LAPD protocol services over GL's T1 E1 boards. It permits to create multiple LAPD links of various bandwidths (time-slots, and sub-channels) and provides UDP interface to the client applications for generating and receiving LAPD payload over these created LAPD streams.

LAPD is also used in GL’s MAPS™ - ISDN to modify LAPD call parameters and message contents to ensure MAPS™ - ISDN communicates with the system under test.

Main Features

Provides multiple data link connections on a single physical link
Ability to detect errors and recover from lost, erred or duplicated information
Releases data link connections
Maintains flow control of transfer of data
Supports Automatic TEI Assignment Procedures
Upon detection of an error it re-initializes data link connections
Supports both User and Network end

Supported Protocols Standards

Supported Protocols	Standard / Specification Used
Q.921 (LAPD)	ITU-T Q.921
SR-4994	National ISDN PRI Standard
Q.931	ITU-T Q.931 / Q.932(Facility IE) / Q.955.3 (MLPP Procedures)
4ESS	ISDN PRI (TR-41449)
5ESS	ISDN PRI (Lucent Tech - 5ESS 2000)
BELL	ISDN PRI (Bell Core SR-NWT-002343)
DMS-100	Nortel's Switch DMS 100 NIS-A2111-1
DMS-250	Nortel's Switch DMS 250 NIS-A2111-4
QSIG ECMA	Standard ECMA-143 4th Edition - December 2001

Syntax

Start LAPD Server Module
run task "LapdServerT[E]1:StartLapD”;
This command invokes the LAPD Server as a special task under GL Server.

Creation of LAPD Links
inform task n "NEW_LAPD_LINK LINKID i TEI j SAPI k USER[NETWORK] STREAM TS|HC|SC LinkSpec";
Provides 2 byte integer number as unique Link ID for all the added links. Assign TEI and SAPI values for the LAPD link. Provides options to select link operation modes, can be either User or Network operation modes and stream configurations to select Hyper Channel, One time-slot, or Sub channels.

Link Statistics
inform task n "GET_STATS LINKID x";
Display statistics for the requested Link ID “x”.

Establishing LAPD links & UDP Transport
inform task n "STARTTRAFFIC ServerPortNumber ClientPortNumber ClientIpAddress";
This command will start the LAPD protocol negotiation [SABME, UA & RR messages] with the DUT on all the added LAPD links. Configures the server with the UDP transport parameters and informs the server to get started for the data [user payload] Tx/Rx over the configured UDP transport.

Example Scripts

run task "LapdServerE1:StartLapD";

                                  inform task 1 "ADDLINK LINKID 1 TEI 0 SAPI 0 NETWORK  STREAM TS #1:16";

                                  inform task 1 "STARTTRAFFIC 22000 33000  192.168.1.23";

                                  inform task 1 "GET_STATS LINKID 1";

                                  inform task 1 "STOP";

Resources:

Please Note: The XX in the Item No. refers to the hardware platform, listed at the bottom of the Buyer's Guide, which the software will be running on. Therefore, XX can either be ETA or EEA (Octal/Quad Boards), PTA or PEA (tProbe Units), XUT or XUE (Dual PCIe Express) depending upon the hardware.

	Related Software
Item No.	Item Description
XX661	LAPD Server
XX642	MAPS™ ISDN & LAPD Conformance Emulator
XX100	ISDN Analysis Software (T1 or E1)
XX120	SS7 Analyzer Software (T1 or E1)
XX130	Real-time Frame Relay Protocol Analyzer (T1 or E1)
XX634	Multi-Channel HDLC Emulation and Analysis & File based High Throughput HDLC Record/Playback
XX640	File based HDLC Record/Playback
	Related Hardware
PTE001	tProbe™ Dual T1 E1 Laptop Analyzer with Basic Analyzer Software
PTE025	Datacom Analyzer Board for RS-232, RS-449, RS-422, RS-423, EIA-530, V.35 Interfaces
TTE001	tScan16™ T1 E1 Boards
XTE001	Dual T1 E1 Express (PCIe) Boards (requires additional licenses)
FTE001	QuadXpress T1 E1 Main Board (Quad Port– requires additional licenses)
ETE001	OctalXpress T1 E1 Main Board plus Daughter Board (Octal Port– requires additional licenses)

Windows Client/Server