I have to agree with Dino about this, and IMHO the performance question is a red herring. My code has been done in the linux kernel, which I realize is far different than optimized fast-path router hardware, but based on what I see there parsing headers is a miniscule component of what goes on in terms of the bigger picture of forwarding a packet.
Fred [EMAIL PROTECTED] >-----Original Message----- >From: Dino Farinacci [mailto:[EMAIL PROTECTED] >Sent: Thursday, July 24, 2008 6:20 PM >To: Christian Vogt >Cc: Drake, John E; Routing Research Group Mailing List >Subject: Re: [RRG] Six/One Router Design Clarifications > >Not true, if you have fixed headers with well known code-points, you >can get to the data you need to parse. It's been done that way for >decades at very high speeds. What hasn't been done at >high-speeds is a >translator. > >With enough thrust anything can fly, but it's easier to do a >decapsulator than a translator. > >Dino > >On Jul 24, 2008, at 2:14 AM, Christian Vogt wrote: > >> >> On Jul 23, 2008, Drake, John E wrote: >> >>>> Talking about performance: An ACL that can limit its looks to >>>> a single place in the IP header (i.e., with translation) can >>>> likely be more efficient that an ACL that needs to look into >>>> an inner IP header behind a pair of LISP and UDP headers. >>> >>> JD: In any map & encap scheme, won't a transit space router have to >>> deal with a multiplicity of packet formats (e.g., both >encapsulated >>> and >>> non-encapsulated packets) and won't it be a performance hit >to figure >>> out a packet's format and then look for the correct fields >within it? >> >> Yep, exactly. >> >> And you avoid this performance hit with translation-based schemes, >> where >> it is always sufficient to look at the addresses in the IP header. >> >> - Christian >> >> >> >> -- >> to unsubscribe send a message to [EMAIL PROTECTED] with the >> word 'unsubscribe' in a single line as the message text body. >> archive: <http://psg.com/lists/rrg/> & ftp://psg.com/pub/lists/rrg > > >-- >to unsubscribe send a message to [EMAIL PROTECTED] with the >word 'unsubscribe' in a single line as the message text body. >archive: <http://psg.com/lists/rrg/> & ftp://psg.com/pub/lists/rrg > -- to unsubscribe send a message to [EMAIL PROTECTED] with the word 'unsubscribe' in a single line as the message text body. archive: <http://psg.com/lists/rrg/> & ftp://psg.com/pub/lists/rrg
