cyrus@hi.unm.edu (Tait Cyrus) (10/01/88)
Before I call IEEE, I was wondering if anyone had a more detailed
list of the 802.2 Link Service Access Points than are listed in
RFC 1010. Currently the RFC has:
00 Null LSAP
02 Indiv LLC Sublayer Mgt
03 Group LLC Sublayer Mgt
04 SNA Path Control
06 DOD IP
0E PROWAY-LAN
4E EIA-RS 511
8E PROWAY-LAN
AA SNAP
FE ISO DIS 8473
FF Global DSAP
The RFC says, "these numbers (and others) are assigned by IEEE....".
My question is what are these "other numbers", or are they
confidinial as are the 48-bit MAC address :^)
Thanks. I will post a summary, assuming I get any replies :^)
---
@__________@ W. Tait Cyrus (505) 277-0806
/| /| University of New Mexico
/ | / | Dept of ECE - Parallel Processing Research Group
@__|_______@ | Albuquerque, New Mexico 87131
| | | |
| | hc | | e-mail:
| @.......|..@ cyrus@pprg.unm.edu
| / | /
@/_________@/rpw3@amdcad.AMD.COM (Rob Warnock) (10/05/88)
In article <23647@hi.unm.edu> cyrus@hi.unm.edu (Tait Cyrus) writes: +--------------- | Before I call IEEE, I was wondering if anyone had a more detailed | list of the 802.2 Link Service Access Points than are listed in | RFC 1010. Currently the RFC has: | ... 06 DOD IP | AA SNAP ... +--------------- NOTA BENE: The use of the "06" LSAP/DSAP is deprecated, in favor of the SNAP-based scheme described in RFC 1042, which gives you the full 16-bit Ethernet types, not just "IP". (This is primarily because the IEEE committee wouldn't allocate a bunch of other types for the other link-level things we all know and love on Ethernet and feel are needed for a useful IP suite: ARP, RARP, BOOTP, etc.) In fact, in RFC 1010, just after the table you mention, is the following section: Due to some evolution of the IEEE 802.2 standards and the need to provide for a standard way to do additional DoD-IP related protocols (such as the Address Resolution Protocol (ARP) on IEEE 802 network, the following new policy is established, which will replace the old policy (see RFC 960 and RFC 948 [108]). The new policy is for the Internet community to use the IEEE 802.2 encapsulation on 802.3, 802.4, and 802.5 networks by using the SNAP with an organization code indicating that the following 16 bits specify the EtherType code (where IP = 2048 (0800 hex), see Ethernet Numbers of Interest). Header ...--------+--------+--------+ MAC Header| Length | 802.{3/4/5} MAC ...--------+--------+--------+ +--------+--------+--------+ | Dsap=K1| Ssap=K1| control| 802.2 SAP +--------+--------+--------+ +--------+--------+---------+--------+--------+ |protocol id or org code =K2| Ether Type | 802.2 SNAP +--------+--------+---------+--------+--------+ The total length of the SAP Header and the SNAP header is 8-octets, making the 802.2 protocol overhead come out on a nice boundary. K1 is 170. The IEEE likes to talk about things in little-endian bit transmission order and specifies this value as 01010101. In big-endian order, as used in Internet specifications, this becomes 10101010 binary, or AA hex, or 170 decimal. K2 is 0 (zero). The use of the IP LSAP (K1 = 6) is to be phased out as quickly as possible. This change was initiated several years ago at the first TCP/IP Interoperability Conference in Monterey, CA. As far as I know, no one but H-P is still using the IP LSAP (and they may have quit by now). Similarly, virtually no one is actually using "802.3" framing; they're all using "Ethernet". The above scheme *is* being used on 802.5 token rings, and is already in use by some people on FDDI. Rob Warnock Systems Architecture Consultant UUCP: {amdcad,fortune,sun}!redwood!rpw3 ATTmail: !rpw3 DDD: (415)572-2607 USPS: 627 26th Ave, San Mateo, CA 94403