Standard for ISO 8072
ISO has issued a standard for a connection-oriented transport service
[ISO 8072], with an identical specification being issued by CCITT
[X.214]. Key characteristics of the transport service, as isted in the
standard are:
Quality of service
selection: The transport service optimizes the use of available
communications resources to provide the requested quality of service at
minimum cost.
Independence of
communications resources: Transport users need not be aware of
quality of service provide by the network service.
End-to-end significance:
Data is transferred between transport service users in end systems.
Transparency of
transferred information: The transport service does not restrict
the content, format, or coding of the user data.
User addressing: A
system of addressing is used that allows transport service users to
refer unambiguously to one another.
The standard specifies a set of parameters that define the quality of
service as observed by transport service users over a transport
connection. The list of parameters is almost identical to that for the
ISO connection-oriented network service. The definitions correspond,
with the following exceptions:
Throughput: The
transport parameters specify average and maximum throughput. The
transport service will attempt to provide the lowest-cost service that
satisfies these parameters.
Transport connection
protection One of four options: (1) no protection features, (2)
protection against passive monitoring, (3) protection against
modification, replay, addition, or deletion, and (4) both (2) and (3).
Resilience of the TC:
Probability of a TC release initiated by a transport service (TS).