thanks for the information all, and to Ping Pan for reminding me that we used to support TOS on the Milford router. I vaguely recall now that was a feature added late in the product lifecycle, so may have only been available on the IBM Global Network. It is a trivia problem at this point. I have sufficient material to revise my lecture notes. Although I want to point out that low delay is RFC 791 back in 1981. It had precedence and TOS specified. I know all routers support the precedence field, and its interesting about the use of TOS and low delay to avoid dial-up links where possible. Dana ----- Original Message ----- From: "William Allen Simpson" <wsimpson@greendragon.com> To: "Dana Hudes" <dhudes@panix.com> Cc: <nanog@merit.edu> Sent: Tuesday, February 22, 2000 5:32 AM Subject: Re: TOS history?
Dana Hudes wrote:
Was this something actually supported in the Internet? Widely? any examples of who? Around when did it stop being supported? Did anyone ever actually support RFC1349 in a host or router?
Yes, on the half-dozen or so routers that I worked on, the low delay bit was supported. This was especially important for dial-up links. (NetBlazer, Lan'sEnd, etc., none of which are in much use today.)
I have also _set_ the low delay bit for telnet traffic on those boxen, but you don't telnet out of routers very often.
I'd have to check the source, but I'm pretty sure I put at least some of that stuff in Qualcomm/Sony cell phones and base stations, so it might still be in use today.
I have also used the TOS bits in a weighted fair queuing scheme.
I never figured out how "high reliability" would be implemented. I just tried to never have low reliability. :-)
WSimpson@UMich.edu Key fingerprint = 17 40 5E 67 15 6F 31 26 DD 0D B9 9B 6A 15 2C 32