cooper@umbc3.UMBC.EDU (Mr. Thaddeus Cooper ) (04/27/89)
I don't really know where to post, this, so I put it here. Someone where I work is working on programming at the Logical link control layer level. Don't ask why we would want to do that, we just do, and is looking for information about how to do that. He has access to the IEEE documents, but is looking for examples, papers, or texts that might be useful. Any help would be appreciated. Please e-mail direct to me at: cooper@devl20.ti.com Thanks very much. -- Thaddeus O. Cooper (cooper@devl20.ti.com) -- -- thad (cooper@umbc3.umd.edu)
haas@wasatch.utah.edu (Walt Haas) (05/02/89)
In article <1955@umbc3.UMBC.EDU>, cooper@umbc3.UMBC.EDU (Mr. Thaddeus Cooper ) writes: > Someone where I work is working on programming at the Logical link control > layer level... and is looking for information about how to do that. Type 1 LLC is trivial. Type 2 is very similar to LAPB, as used by X.25, so any good X.25 implementation should serve as a suitable starting point. Cheers -- Walt Haas haas@cs.utah.edu utah-cs!haas
larry@pluto.paradyne.com (Larry Swift) (05/02/89)
In article <1702@wasatch.utah.edu> haas@wasatch.utah.edu (Walt Haas) writes: >Type 1 LLC is trivial. Type 2 is very similar to LAPB, as used by X.25, >so any good X.25 implementation should serve as a suitable starting point. This is very surprising, since LAPB is a connection-oriented, flow-controlling protocol and Ethernet is a connectionless, free-flowing medium. Can you explain the differences and similarities between Type 2 & LAPB? Larry Swift UUCP: {peora,uunet}!pdn!larry AT&T Paradyne, LG-129 Phone: (813) 530-8605 P. O. Box 2826 Largo, FL, 34649-9981 She's old and she's creaky, but she holds!
haas@wasatch.utah.edu (Walt Haas) (05/04/89)
In article <6048@pdn.paradyne.com>, larry@pluto.paradyne.com (Larry Swift) writes: > In article <1702@wasatch.utah.edu> haas@wasatch.utah.edu (Walt Haas) writes: > >Type 1 LLC is trivial. Type 2 is very similar to LAPB, as used by X.25, > >so any good X.25 implementation should serve as a suitable starting point. > > This is very surprising, since LAPB is a connection-oriented, > flow-controlling protocol and Ethernet is a connectionless, > free-flowing medium. Can you explain the differences and similarities > between Type 2 & LAPB? Well, referring to Chapter 5 of IEEE 802.2, we see that the 802.2 LLC PDU control fields are 16 bits long with 7 bits allocated to sequence numbers, whereas LAPB control fields are 8 bits long with 3 bits allocated to sequence numbers. XID is as far as I know unique to 802.2. 802.2 frames begin with a DSAP/SSAP pair which do not exist in LAPB. Other differences seem to be mostly terminology. Type 2 LLC does indeed establish a reliable, flow-controlled path between two hosts on a[n] 802.[345] network[s]. Cheers -- Walt Haas haas@cs.utah.edu utah-cs!haas