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QoS Service Types in Office Communications Server

Microsoft Office Communications Server 2007 and Microsoft Office Communications Server 2007 R2 will reach end of support on January 9, 2018. To stay supported, you will need to upgrade. For more information, see Resources to help you upgrade your Office 2007 servers and clients.

The Office Communications Server 2007 media subsystem in Office Communication Server uses the following two ServiceType values:

  • SERVICETYPE_GUARANTEED

  • SERVICETYPE_CONTROLLEDLOAD

The SERVICETYPE_GUARANTEED setting guarantees that IP datagrams will arrive within the guaranteed delivery time and will not be discarded due to queue overflows, provided the flow's traffic stays within its specified traffic parameters. This service is intended for applications that need a firm guarantee that a datagram will arrive no later than a certain time after it was transmitted by its source.

The Real Time Media Communications stack marks the RTP/SRTP Audio packets (default payload type value equal to 0, 3, 4, 8, 111, 112, 114, 115, or 116) as SERVICETYPE_GUARANTEED.

The SERVICETYPE_CONTROLLEDLOAD setting provides an end-to-end QOS that closely approximates transmission quality provided by best-effort service, as expected under unloaded conditions from the associated network components along the data path.

Applications that use SERVICETYPE_CONTROLLEDLOAD may therefore assume the following:

  • The network will deliver a very high percentage of transmitted packets to its intended receivers. In other words, packet loss will closely approximate the basic packet error rate of the transmission medium.

  • Transmission delay for a very high percentage of the delivered packets will not greatly exceed the minimum transit delay experienced by any successfully delivered packet.

The Real Time Media Communications stack marks the RTP/SRTP Video packets (default payload type value equal to 34 or 121) as SERVICETYPE_CONTROLLEDLOAD.