BCP regarding TOS transparancy for internet traffic

Wed May 25 18:18:42 UTC 2005

On May 25, 2005, at 10:39 AM, Sam Stickland wrote:

> While it's true that IP is end-to-end, are fields such as TOS and DSCP 
> meant to be end to end? A case could be argued that they are used by 
> the actual forwarding devices on route in order to make QoS or even 
> routing decisions, and that the end devices shouldn't actually rely on 
> the values of these fields?

It used to be that TCP would reset a session if the TOS byte changed in 
mid-session. That certainly sounds like an end-to-end expectation.