Re: QoS, DSCP and IPprecedence backward compatibility
What might help clarify this is to realize that the ToS byte and DiffServ Field is the same byte/field, it's just the interpretation of the bits differ between the older and newer standards. The newer standard, DSCP, attempts to use the first 3 bits, those used by IP Precedence, in much the same way, for the packet's priority class. This so packets might be treated alike whether using the older standard or the newer standard.
Second, also realize, it's left to the equipment whether it can support either standard, and to the configuration whether anything is done with this byte on the equipment.
By default, this byte should pass through all equipment as set by the source. However, each device that understands the byte, might or might not adjust the packet's processing, and/or might or might not change the value. This regardless of whether the old or new standard is being used.
"What happens if A sends frames to B, marking those using a specific DSCP value (ex. AF11)?"
The answer is:
"3) Neither 1 or 2....(your explanation here"
Node B, if using IP Precedence, will see the packet as an IP Precence 1. But it could also see it also marked for "high throughput".
BTW: Cisco supported using one more ToS bit for min-monetary-cost.
We are pleased to announce availability of Beta software for 16.6.3.
16.6.3 will be the second rebuild on the 16.6 release train targeted
towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are
looking for early feedback from customers befor...
Introduction Featured Speakers Luis Espejel is the Telecommunications
Manager of IENova, an Oil & Gas company. Currently he works with Cisco
IOS® and Cisco IOS XE platforms, and NX to some extent. He has also
worked as a Senior Engineer with the Routing P...
In this session you can learn more about Layer 3 multicast and the best
practices to identify possible threats and take security measures. It
provides an overview of basic multicast, the best security practices for
use of this technology, and recommendati...