From owner-freebsd-isdn Sat Dec 2 1: 0:28 2000 Delivered-To: freebsd-isdn@freebsd.org Received: from worker.thw-IP.NET (worker.thw-IP.NET [192.76.134.35]) by hub.freebsd.org (Postfix) with ESMTP id D435537B401 for ; Sat, 2 Dec 2000 01:00:23 -0800 (PST) Received: from localhost (2973 bytes) by worker.thw-IP.NET via rmail with P:stdio/R:inet_mx_hosts/T:inet_zone_smtp (sender: ) (ident using unix) id for ; Sat, 2 Dec 2000 10:00:16 +0100 (CET) (Smail-3.2.0.111 2000-Feb-17 #18 built 2000-Oct-9) Received: from bert.kts.org (bert.kts.org [194.55.156.2]) by ernie.kts.org (Postfix) with ESMTP id 066B752ABA; Sat, 2 Dec 2000 09:41:12 +0100 (CET) Received: by bert.kts.org (Postfix, from userid 100) id ECED69B1C; Sat, 2 Dec 2000 09:41:11 +0100 (CET) Subject: Re: cisco hdlc [was: i4bing -> panic] In-Reply-To: from "Bjoern A. Zeeb" at "Dec 1, 2000 11:23:16 pm" To: i4b@zabbadoz.net (Bjoern A. Zeeb) Date: Sat, 2 Dec 2000 09:41:11 +0100 (CET) Cc: hm@hcs.de, freebsd-isdn@FreeBSD.ORG Organization: Kitchen Table Systems Reply-To: hm@kts.org X-Mailer: ELM [version 2.4ME+ PL43 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Content-Length: 1983 Message-Id: <20001202084111.ECED69B1C@bert.kts.org> From: hm@kts.org (Hellmuth Michaelis) Sender: owner-freebsd-isdn@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Bjoern A. Zeeb wrote: > --- snipp --- > HDLC is used for the IP over ISDN interfaces ipr and isp. In case of > the ipr driver, IP frames are put directly into those HDLC frames and > sent to the remote site; in the case of isp IP frames are encapsulated > into PPP frames which in turn are put into the HDLC frames. > --- snipp --- ipr driver: +------------+--------------------------------------+----------+-----------+ | HDLC flag | IP - packet | HDLC CRC | HDLC flag | +------------+--------------------------------------+----------+-----------+ isp and userland ppp: +------------+--------------------------------------+----------+-----------+ | HDLC flag | PPP frame (see below) | HDLC CRC | HDLC flag | +------------+--------------------------------------+----------+-----------+ | PPP head | IP - packet | PPP trailer | +--------------------------------------+ > ok. now there are two types of keepalives: > 1. cisco hdlc slarp keepalives > 2. "ppp keepalives" > that have nothing in common that the part of the name (highly > simplified). Correct. AFAIK, Cisco HDLC is more like the ipr way of doing things with the addition of adding a second encapsulation providing a "packet" type to distinguish between control packets (i.e. keepalives) and data packets (payload data). > So why is cisco hdlc implemented in isp instead of ipr if it is only > using "raw hdlc" with slarp extetions ? I don't know. It is part of the sppp subroutine set. Was it perhaps phk who added this (Poul-Henning, are you listening ?). > So what I would have to use is ipr with slarp extentions. This would be a natural way if it was not there, but i think it is already there in the isp/isppp interface, so why do doubled work ? hellmuth -- Hellmuth Michaelis hm@kts.org Hamburg, Europe We all live in a yellow subroutine, yellow subroutine, yellow subroutine ... To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-isdn" in the body of the message