To: P8021 Cc: Brian Ramelson/ENG/WEBO/PROMDOM1 From: Steve Horowitz Date: 21 Jun 96 19:12:49 Subject: Priority Service and 802.3 Flow Control Hi, I am raising this issue without having read the 802.3 flow control specification .... That said, what happens if we have multiple levels of queueing service for the multiple levels of priority, and one of the queues fills up? As I understand it today, if you send an 802.3 pause frame, all traffic is paused. This, of course, has the unintended effect of also pausing the frames of the other priorities that may actually have queue space available. I would recommend one of two approaches to fix this problem. 1. The pause frame only applies to normal priority queues and their associated traffic. The thinking behind this is that the higher priority traffic is likely to be time sensitive and pausing that traffic, well you might as well drop it anyway. 2. Allow the pause frame to have priority intelligence. I believe that this is allowed in the spec that I did not read, but is it described anywhere? Anyway, I think that as part of our work with priorities, we need to liason with 802.3 to make sure that this works on Ethernet networks that have flow control. Comments are welcome. I apologize in advance if this is a non-issue. In the meantime, I'll try to grab the latest draft to follow up. -- Steve