Browse Prior Art Database

Protocol for Enveloping and Routing LPDA2 (Pearl)

IP.com Disclosure Number: IPCOM000035126D
Original Publication Date: 1989-Jun-01
Included in the Prior Art Database: 2005-Jan-28
Document File: 2 page(s) / 69K

Publishing Venue

IBM

Related People

Bauchot, F: AUTHOR

Abstract

Link Problem Determination Aid Version 2 (LPDA2) is a protocol supported by IBM Signal Converter Products (SCPs) to exchange Communication Network Management (CNM) data with the Data Terminal Equipment (DTE) to which they are attached. The CNM information is carried in LPDA2 frames which flow 'mainstream' on the regular data path. A new protocol is disclosed which allows the transport of CNM information (that is LPDA2 data) either 'mainstream' on the regular data path or 'sidestream' on a 'service' path. This protocol defines on the first hand a frame used to carry the CNM information (referred to as the PEARL frame) and on the other hand the flow of PEARL frames along the different paths. The PEARL command originator is not necessary connected to the target SCP.

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Protocol for Enveloping and Routing LPDA2 (Pearl)

Link Problem Determination Aid Version 2 (LPDA2) is a protocol supported by IBM Signal Converter Products (SCPs) to exchange Communication Network Management (CNM) data with the Data Terminal Equipment (DTE) to which they are attached. The CNM information is carried in LPDA2 frames which flow 'mainstream' on the regular data path. A new protocol is disclosed which allows the transport of CNM information (that is LPDA2 data) either 'mainstream' on the regular data path or 'sidestream' on a 'service' path. This protocol defines on the first hand a frame used to carry the CNM information (referred to as the PEARL frame) and on the other hand the flow of PEARL frames along the different paths. The PEARL command originator is not necessary connected to the target SCP. The PEARL framing is as follows: F : SDLC Flag A : SDLC Address Field C : SDLC Control Field H : LPDA2 Header HE : PEARL Header Extension (X'23' if downstream, X'63' if upstream) SA : Service Address Field CNMI: CNM Information Field FCS : SDLC Frame Check Sequence

According to the structure of this frame, it is unique with respect to the following Data Link Controls: SDLC, BSC, ALC and also to LPDA2.

As PEARL frame can flow either on the data or on the service path, a mechanism tells each SCP whether or not to switch from one path to the other one. The Service Address field of the PEARL frame represents the entire route the PEARL frame must follow from t...