Znyx Networks bh5700 manual Combining Queuing Disciplines, Cops Common Open Policy Service

tc filter add dev zhp0 protocol arp parent 100:0 u32 match u32 2 0xffff at +4 flowid 100:30

Combining Queuing Disciplines

Any of the queue length limiting disciplines can be used with the bandwidth management queue disciplines, by defining them with the handle of one of the classes as their parent. For the htb queueing discipline, each class has an explicit handle specified when it is defined. For the prio queueing discipline, including wrr, each band is a class; their handles are formed from the handle of the prio qdisc by appending a minor number of 1 to n for the n bands. For example, the following commands define two strict priority queues for port zre5, with the lower priority queue limited to 32 kb and the higher priority queue limited to 32 kb:

tc qdisc add dev zre5 root handle 100:0 prio bands 2 priomap 0 0 0 0 1 1 1 1

tc qdisc add dev zre5 parent 100:1 handle 110:0 bfifo limit 32kb tc qdisc add dev zre5 parent 100:2 handle 120:0 bfifo limit 32kb

These translation rules handle conversions of individual rules from tc entries into hardware entries. They do not explain the results of creating rules that are individually supported; but which do not make sense in conjunction.

Although the translation rules handle some inconsistency between software and hardware, a user must define a combination of rules that is reasonable in hardware, to ensure predictable results.

Handle Semantics

All examples have illustrated zqosd copying tc rules into hardware. In fact, the zqosd utility also enables the user to add tc rules that remain only in software. This selection is based on handles. zqosd processes all supported queue disciplines and filters with handles between 100:0 and 200:FFFF.

COPS: Common Open Policy Service

The Common Open Policy Service (COPS) is a protocol for distributing networking policy to devices such as switches and routers. COPS allows a single Policy Decision Point (PDP) to distribute policy to multiple Policy Enforcement Points (PEPs). A PDP acts as a server for PEP clients. Figure 7.6 provides an illustration of the COPS Network Architecture.

Ethernet Switch Blade User's Guide release 3.2.2j page 124