Browse Prior Art Database

Error Detection/ Recovery for Link Activation Protocol

IP.com Disclosure Number: IPCOM000109041D
Original Publication Date: 1992-May-01
Included in the Prior Art Database: 2005-Mar-23
Document File: 1 page(s) / 57K

Publishing Venue

IBM

Related People

Drake, JE: AUTHOR [+2]

Abstract

Link activation protocols typically require the same error detection and error recovery mechanisms that are found in higher level (i.e., transport) protocols, and most link activation protocols duplicate these mechanisms. This problem of function duplication is addressed by describing a link activation protocol that uses a transport level protocol to provide these mechanisms.

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Error Detection/ Recovery for Link Activation Protocol

      Link activation protocols typically require the same error
detection and error recovery mechanisms that are found in higher
level (i.e., transport) protocols, and most link activation protocols
duplicate these mechanisms.  This problem of function duplication is
addressed by describing a link activation protocol that uses a
transport level protocol to provide these mechanisms.

      As an example, the APPN link activation protocol (XID3)
includes the following functions:
.   Distinguishing between a request and a response
.   Retransmitting lost packets
.   Discarding duplicate packets
.   Handling the situation of both nodes simultaneously sending
requests

      It is proposed that the link activation protocol use a
transport protocol to provide the functions enumerated in the
previous paragraph, which is considerably simpler and more robust.
This transport protocol allows a packet that initiates a connection
to be distinguished from other packets and user data to be included
in the first packet flowing in each direction.  It consists of a
single message exchange (i.e., a link activation request and a link
activation response) on a short-lived, reliable transport connection
between the nodes activating the link.

      The reliable transport protocol allows a node to determine that
a received link activation message is a request if it flows on a
connection initiation packet. Otherwise,...