WCS LAPD Server over T1 E1
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.
- 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
||Standard / Specification Used
||National ISDN PRI Standard
||ITU-T Q.931 / Q.932(Facility IE) / Q.955.3 (MLPP Procedures)
||ISDN PRI (TR-41449)
||ISDN PRI (Lucent Tech - 5ESS 2000)
||ISDN PRI (Bell Core SR-NWT-002343)
||Nortel's Switch DMS 100 NIS-A2111-1
||Nortel's Switch DMS 250 NIS-A2111-4
||Standard ECMA-143 4th Edition - December 2001
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.
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.
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";
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), UTA or UEA (USB Units), HUT or HUE (Universal Cards), and HDT or HDE (HD cards) depending upon the hardware.