SIP-SDP DCSP Marking ToS Bit Manipulation
Used to indicate priority and type of requested service to devices in the network, type of service (TOS) information is included as a set of four-bit flags in the IP header. Each bit has a different purpose, and only one bit at a time can be set: There can be no combinations. Available network services are:
- Minimum delay—Used when latency is most important
- Maximum throughput—Used when the volume of transmitted data in any period of time is important
- Maximum reliability—Used when it is important to assure that data arrives at its destination without requiring retransmission
- Minimum cost—Used when it is most important to minimize data transmission costs
The Oracle® Enterprise Session Border Controller’s support for type of service (TOS allows you to base classification on the media type as well as the media subtype. In prior releases, you can configure the Oracle® Enterprise Session Border Controller to mark TOS bits on outgoing packets using a media policy. Supported media types include audio, video, application, data, image, text, and message; supported protocol types are H.225, H.245, and SIP. Note that, although H.225 and H.245 are not part of any IANA types, they are special cases (special subtypes) of message for the Oracle® Enterprise Session Border Controller. When these criteria are met for an outgoing packet, the Oracle® Enterprise Session Border Controller applies the TOS settings to the IP header. The augmented application of TOS takes matching on media type or protocol and expands it to match on media type, media-sub-type, and media attributes.
The new flexibility of this feature resolves issues when, for example, a customer needs to differentiate between TV-phone and video streaming. While both TV-phone and video streaming have the attribute “media=video,” TV-phone streaming has “direction=sendrcv” prioritized at a high level and video has direction=sendonly or recvonly with middle level priority. The Oracle® Enterprise Session Border Controller can provide the appropriate marking required to differentiate the types of traffic.
In the media policy, the tos-values parameter accepts values that allow you to create any media type combination allowed by IANA standards. This is a dynamic process because theOracle® Enterprise Session Border Controller generates matching criteria directly from messages.
The new configuration takes a media type value of any of these: audio, example, image, message, model, multipart, text, and video. It also takes a media sub-type of any value specified for the media type by IANA; however, support for T.38 must be entered exactly as t.38 (rather than t38). Using these values, the Oracle® Enterprise Session Border Controller creates a value Based on a combination of these values, the Oracle® Enterprise Session Border Controller applies TOS settings.
You also configure the TOS value to be applied, and the media attributes you want to match.
You can have multiple groups of TOS settings for a media policy.
