Date: Wed, 22 Apr 1998 10:02:44 -0500 From: Paul_Labadie@tivoli.com Cc: tokenring@FreeBSD.ORG Subject: Re: Current work... Message-ID: <852565EE.004C23D7.00@notes-brahms2.tivoli.com>
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- > On Tue, 21 Apr 1998, Paul Norton wrote: > > Two bytes for the RCF and 16 bytes for the route fields. > > 3.2.5 Routing information (RI) field > > When a frame's routing information indicator bit in the source address > field is equal to 1 (RII=1), the RI field shall be included in the frame. > The following provides sufficient information for the MAC entity to > determin the size of the RI field and parse the frame properly. The > detailed structure and contents for the RI field is described in ISO/IEC > 10038:1993 and ISO/IEC 88022-2 : 1994 > > <- RI Field (Length represented by LTH Field) -> > | | > +------+--------+------------------------------+ > | 3 | LTH | | > | bits | 5 bits | | > +------+--------+------------------------------+ > > RI = Routing Information (2 to 30 octets when present) > LTH = Lenght (5 bits) (number of octets) > The first 3 bits are for broadcast type, tradition at IBM is to allow only 7 'hops' or 7 2byte segment number/bridgenumber addons to the 2 byte control field (the broadcast and length are just the first byte), although recently its been upped to 13. not sure how most drivers handle the packet when there is no RIF, first 3 bits 0XX = Non-Broadcast 10X = All-Route Broadcast 11X = Single-route broadcast X means either a 1 or a 0. since the information field follows the RI, i never understood how a driver knows if the next field is an IF, RIF or the CRC/end code. l8r, p > > Yes, but you really need to tell the user when they attempt to configure > > the interface with an invalid MTU as well. Otherwise their first clue > > that they've misconfigured the interface is that some connections just > > don't work. > > iso88025subr.c : iso88025_ioctl() must insure that such misconfiguration > will not happen. > > And will when I get a chance to write it. :) I am already working on iso88205_ioctl that is why I was trying to determine the limits for 802.5. Larry lile@stdio.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-tokenring" in the body of the message To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-tokenring" in the body of the message
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