Per-Service Data Header

The above object header is followed by one or more service-specific blocks. Each block consists of a 32-bit header identifying a service and the service-specific QoS control information.

MSB                                                           LSB
31            24 23           16 15                            0
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|  Svc_Number   |B| Reserved    |            Svc_Length         |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Svc_Number:

8 bits
The service ID number as defined in a service specification, for example in [Wro96b] for Controlled-Load Service or in [SPG96] for guaranteed service.

B:

1 bit
Break bit: set to 1 if the service is unsupported somewhere in the path, 0 if all hops support this service.

Svc_Length:

16 bits
The service-specific data block length in 32-bit words, not including the header.