RE: [Manet-dt] DYMO Routing Information Freshness Check

["Koojana Kuladinithi" <[e-mail]>]

Hi Ian,

Under the Node.SeqNum == Route.SeqNum condition, you now assume that RM
information is loop prone, if If Node.HopCnt >
      Route.HopCnt + 1,.

In the earlier version, you have checked the above condition when
comparing only with invalid routes. Now, you are doing it for both valid
& invalid route info. Is there any reason that you have changed this?

Koojana 

> -----Original Message-----
> From: Ian Chakeres [mailto:[e-mail]] 
> Sent: 25 June 2006 22:16
> To: Koojana Kuladinithi
> Cc: [e-mail]
> Subject: Re: [Manet-dt] DYMO Routing Information Freshness Check
> 
> 
> About the second part of your email. I've revised that area 
> (inferior). Here is the new text. This allows Node.SeqNum == 
> Route.SeqNum+1 if the route is invalid. It also allows 
> Node.SeqNum == Route.SeqNum if the message is a RREP. I might 
> be missing a case, please give it a read and let me have your 
> comments.
> 
> Thanks.
> Ian
> 
> 5.2.1.  Judging New Routing Information's Usefulness
> 
>    Given a routing table entry (Route.SeqNum, Route.HopCnt, and
>    Route.ValidTimeout) and new routing information for a 
> particular node
>    in a RM (Node.SeqNum, Node.HopCnt, and RM message type - 
> RREQ/RREP),
>    the quality of the new routing information is evaluated to 
> determine
>    its usefulness.  The following comparisons are performed in order:
> 
>    1. Stale
>       If Node.SeqNum - Route.SeqNum < 0 (using signed 16-bit 
> arithmetic)
>       the information is stale.  Using stale routing 
> information is not
>       allowed, since doing so might result in routing loops.
> 
>    2. Loop-prone
>       If Node.SeqNum == Route.SeqNum the information maybe loop-prone,
>       additional information must be examined.  If Route.HopCnt is
>       unknown or set to zero (0), then the routing 
> information is loop-
>       prone.  Likewise, if Node.HopCnt is unknown or set to zero (0),
>       then the routing information is loop-prone.  If Node.HopCnt >
>       Route.HopCnt + 1, then the routing information is loop-prone.
>       Using loop-prone routing information is not allowed, since doing
>       so might result in routing loops.
> 
>    3. Inferior
>       If Node.SeqNum == Route.SeqNum the information may be inferior,
>       additional information must be examined.  If the route is valid
>       (by examining Route.ValidTimeout and the current time), then the
>       new information is inferior if Node.HopCnt > 
> Route.HopCnt.  If the
>       route is valid, then the new information is also inferior if
>       Node.HopCnt == Route.HopCnt AND this RM is a RREQ.
> 
>    4. Fresh
>       Routing information that does not match any of the 
> above criteria
>       is loop-free and better than the information existing in the
>       routing table.  This information should be used to update the
>       routing table.
> 


_______________________________________________
Manet-dt mailing list
[e-mail]
https://www1.ietf.org/mailman/listinfo/manet-dt