l layer Digital section level 2. VC Link: VC between two consecutive ATM entities where the VC Identifier (VCI) value is translated. A specific value of VCI Regenerator section level is assigned each time a VC is switched in the network. VC routing: translation of VCI values between the incoming and outgoing links on a VC switch. Figure 41.11 Relationship between VC, VP transmission VC Connection (VCC): concatenation of VC links. Extends path (Fig. 1/1.311) and hierarchy of the ATM transport between two VCC endpoints (more than two for point to multi- network (Fig. 2/1.311) point). Provided for user-user, user-network, network-network information transfer. Cell sequence integrity is preserved by the ATM layer within a VCC. 5. VCC endpoint: where cell information field is exchanged be- I.311 explores the identified applications of VCCs and VPCs, tween the ATM layer and the user of the ATM Layer Service. categorising each as user-user, user-network and network-network. 6. Virtual Path (VP): generic term for a bundle of virtual channel In each application the connection end-points are localised and an links. All VC links in the bundle have the same endpoints. indication of possible use given. 7. VP Link: unidirectional capability for transport of ATM cells between two consecutive ATM entities where the VP Identifier (VPI) value is translated. A specific value of VPI is assigned 41.4.5.2 Signalling principles each time a VP is switched in the network. VP routing: translation of VPI values between the incoming This identifies the signalling capabilities required in B-ISDN to and outgoing links on a VP switch. support a multiplicity of service types and covers the requirements 41/12 Asynchronous Transfer Mode VC link Virtual channel connection Virtual channel level VP link Virtual path connection Virtual level Transmission path Transmission level Digital section Digital section level Regenerator section Regenerator section level Endpoint of the corresponding levels Connecting point of the corresponding levels Figure 41