Subject: Reliable delivery of control Messages

From: Sridhar Malarothu <[email-masked]>
Date: Wed, 30 Aug 2000 13:33:40 +0530

Hi All,

   Should Acknowledgement for a control message (if it has been 
received in order) be always piggy-backed on to the repsonse 
message (if one exists exists) ? If not then its better to start 
timers when replies for some control messages are awaited.

   I want some clarification on synchronous framing for PPP. PPP
will not add link framing (flags 0x7e) and crc bytes. but what 
about the async mapping for synchronous lines? 
 
Best Regards
Sridhar

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From: Motonori Shindo <[email-masked]>
Date: Wed, 30 Aug 2000 20:37:40 +0900 (JST)

Sridhar,

From: Sridhar Malarothu <[email-masked]>
Subject: Reliable delivery of control Messages
Date: Wed, 30 Aug 2000 13:33:40 +0530

> message (if one exists exists) ? 

It should but it's not mandatory.

> If not then its better to start 

Whenever a control message is sent, a timer associated with it should
be started. The only exception to this rule is a ZLB. Since ZLB
doesn't consume a sequence number space, timer invocation is not
necessary. As a consequence, ZLB will not be retransmitted.

> will not add link framing (flags 0x7e) and crc bytes. 

True.

> but what 

Sorry, I don't understand your question. Someone else will shed more
light on this.

Regards,

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