🚀 go-pugleaf

 > Date: Sun, 19 Aug 90 23:10:54 PDT
 > From: Jim Forster <forster@cisco.com>
 > 
 > Bob,
 > 
 > Sorry, we don't support TOS routing.  4.4BSD is rumored to have such
 > capability, but I don't know of anyone that has it now. 
 > 
 > In 8.2 we do support TOS queueing.  After routing, the packet is placed on
 > one of 4 output queues.  The factors that influence which queue can include
 > protocol, and whether the packet matches an access list.  So you can make
 > Bridged LAT & Telnet higher priority than FTP, for instance.  We don't
 > use packet size in deciding which queue to use.  How do you think packet size
 > should be used?

While the capability described above is a step in the right direction,
I would prefer to be able to configure my routers so that any packet
with length <= N is queued before any packet > N.  This way all character
echo traffic (and other short packets) get sent out before longer
file transfer traffic.  I would hope that I could pick N (e.g., in case
I had telnet/rlogin and not xterm, or vice versa).

If I understand the queueing in 8.2, keyed on access list, I would
have to set up an access list for each application protocol I wanted to
flag for special queueing.  This means that the router has to delve
into the headers to look at every packet (slowing things down?) and
that I have to identify all the application ports (telnet, rlogin,
xterm, in-house applications, etc.) that I might like to give higher
priority.  This type of queueing is particularly important with slower
speed serial lines (less than full T1) that already have long
serialization and propagation times (e.g., international links).

Of course, support for real TOS would be nice (but then we'd also
have to hammer on our host software providers to specify TOS in the
packets the applications send--and we know how responsive they are ;-).

Greg Wetzel	(708) 979-4782	G_F_Wetzel@att.com

AT&T Bell Laboratories (IH 1B-213)
2000 N. Naperville Road
Naperville, IL  60566