How do I create optimizer policies based on ToS/DSCP value?
See Policies.
The ToS (type of service) or DiffServ (differentiated services) field in the IPv4 header, and the Traffic Class field in the IPv6 header are industry standard fields used to classify IP packets so that routers can make QoS (quality of service) decisions about what path packets should traverse across the network. Exinda appliances can read and write ToS/DSCP marks in packets, allowing users fine-grained control and classification of applications that are marked with ToS/DSCP values as well as applying marking policies to ensure traffic is treated appropriately by onward network equipment. For example, users may want to ensure that VoIP uses high quality, low latency (and expensive) links, or, they might want to ensure email or recreational traffic uses cheaper (but less reliable) links.
Used in conjunction with the Exinda classification techniques, including advanced layer 7 detection, users have complete control over how traffic is marked, and subsequently treated in the WAN cloud.
Previously, there were 5 different categories that users could use to classify their traffic with the IP ToS field (see RFC 791): Normal Service, Minimize Cost, Maximize Reliability, Maximize Throughput, and Minimize Delay. These have since been replaced by a new set of values called DSCP (DiffServ Code Points, see RFC 2474). A DSCP is a 6-bit number; therefore, there are 64 possible DSCP combinations, of which, only a portion have been standardized. IPv6 contains an 8 bit Traffic Class field. The 6 most significant bits are treated the same as IPv4 DSCP. The least 2 significant bits are not modified by the appliance.
All Exinda products can read and write the ToS/DiffServ field, allowing users to:
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