Virtual Path / Channel Connection Uses

1. Between end users: Can be used to carry end-to-end user data; can also be used to carry control signaling between end users, as explained later. A VPC between end users provides them with an overall capacity; the VCC organization of the VPC is up to the two end users, provided the set of VCCs does not exceed the VPC capacity.

2.Between an end user and a network entity: Used for user-to-network control signaling, as discussed subsequently. A user-to-network VPC can be used to aggregate traffic from an end user to a network exchange or network server.

3. Between two network entities: Used for network traffic management and routing functions. A network-to-network VPC can be used to define a common route for the exchange of network management information.

Virtual Path/Virtual Channel Characteristics

1. Quality of service (QoS): A user of a VCC is provided with a QoS specified by parameters such as cell loss ratio (ratio of cells lost to cells transmitted) and cell delay variation.

2. Switched and semipermanent virtual channel connections: A switched VCC is an on-demand connection, which requires a call control signaling for setup and tearing down. A semipermanent VCC is one that is of long duration and is set up by configuration or network management action.

3. Cell sequence integrity: The sequence of transmitted cells within a VCC is preserved.

4. Traffic parameter negotiation and usage monitoring: Traffic parameters can be negotiated between a user and the network for each VCC. The network monitors the input of cells to the VCC, to ensure that the negotiated parameters are not violated.

5. Virtual channel identifier restriction within a VPC: One or more virtual channel identifiers, or numbers, may not be available to the user of the VPC but may be reserved for network use. Examples include VCCs used for network management.