Date: Wed, 15 Nov 2000 08:24:08 -0600 (CST) From: lgfausak@august.net (Greg Fausak) To: alex@pilosoft.com, gcorcoran@lucent.com Cc: freebsd-net@FreeBSD.ORG Subject: Re: netgraph/atm Message-ID: <m13w3Ts-002H2XC@gomer.august.net>
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> >On Tue, 14 Nov 2000, Gary T. Corcoran wrote: > >> > yep.. If that's what rfc1483 (the rfc) treats as input and output. >> >> Actually RFC1483 has four "flavors", two of which support "bridging" >> of complete 802.3 ethernet frames including the MAC addresses - either >> encapsulated with an LLC/SNAP header or "raw" with just a two byte >> (0x00, 0x00) pad for alignment purposes. Another flavor removes the >> MAC addresses, prepends a 6-byte LLC/OUI header, and preserves the >> EtherType and the rest of the frame. The other flavor just routes >> a PDU (raw packet with no MAC addressses or EtherType) across a VC >> (ATM virtual channel) with no encapsulation at all. >Yeah. I'm just implementing it to scratch my itch, and I'll see about >support of everything else later. I'm definitely going to try to support >llc/snap and raw mode. Without the ethertype, its 'routed PDU', and is >already handled just fine by existing ATM stacks. > >> Alex - if you intend to make your code public, and if you feel >> ambititious, it would be nice if you could support all four flavors >> of RFC1483. Then we could replace our Win2000 server with a FreeBSD >> server for testing our DSL implementations of RFC1483... ;-) >Yes, we are also doing it for DSL. Its quite unfortunate that telcos chose >'bridged mac/llc' as preferred method of delivery of DSL, since it has the >biggest overhead...But I guess for them transparency was the biggest >issue. Oh well. FWIW: One of the guys I work with did the DSL implementation for GTE. I asked him about the choice of bridging. He indicated that there are some legal reasons that bridged connections are delivered rather than routed connections. ---greg Greg Fausak August.Net Services, LLC greg@august.net 972-323-6598 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message
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