SSH EN 301 217-1 V1.2.2:1999

Ndërfaqet V në Nyjen e Shërbimit dixhital (SN); Ndërfaqet në pikën e referimit VB5.2 për mbështetjen e Aksesit në Rrjet (ANs) me brez të gjerë frekuence ose të kombinuar me bandë të ngushtë dhe me brez të gjerë frekuence; Pjesa 1: Specifikim i ndërfaqes

V interfaces at the digital Service Node (SN); Interfaces at the VB5.2 reference point for the support of broadband or combined narrowband and broadband Access Networks (ANs); Part 1: Interface specification

Scope

The present document specifies the physical, procedural and protocol requirements for interfaces at the VB5.2 reference
point between an Access Network (AN) and a Service Node (SN). The VB5.2 reference point provides flexible
(provisioned) virtual path (VP) link allocation and flexible (provisioned) virtual channel (VC) link allocation (controlled
by the Q3 interfaces) as well as on-demand VC link allocation controlled by the SN via the broadband bearer connection
control (B-BCC) protocol. That is, the VB5.2 reference point is a superset of the VB5.1 reference point, enabling
on-demand VC link allocation in the AN and across the VB5 reference point via the additional B-BCC function.
The following B-ISDN customer access types with the general user network interface (UNI) characteristics defined in
ITU-T Recommendation I.432.1 [33] are supported:
a) B-ISDN accesses with a UNI at 155 520 kbit/s and 622 080 kbit/s according to
ITU-T Recommendation I.432.2 [34], i.e.:
1) SDH based according to ETS 300 300 [4];
2) Cell based according to ETS 300 299 [3].
b) B-ISDN access with a PDH based UNI at 1 544 kbit/s and 2 048 kbit/s according to
ITU-T Recommendation I.432.3 [35].
c) B-ISDN accesses with a UNI at 51 840 kbit/s or 25 600 kbit/s according to
ITU-T Recommendations I.432.4 [36] and I.432.5 [37].
B-ISDN accesses with a UNI according to future ENs and/or ITU-T Recommendations may require additional
functionality at the VB5.2 reference point.
In order to provide for a migration from narrowband to broadband access network and service node arrangements, also
narrowband access types as specified for:
- V5.1 interface according to ETS 300 324-1 [6]/ITU-T Recommendation G.964 [20]; and/or
- V5.2 interface according to ETS 300 347-1 [7]/ITU-T Recommendation G.965 [21],
are also supported according to the integration scenario given in Appendix III.2.2 of
ITU-T Recommendation G.902 [19], using a circuit emulation function for the transfer of circuit mode into ATM.
In addition to these B-ISDN and narrow-band customer access types, other non-B-ISDN access types are also supported.
Examples for such non-B-ISDN access types are given below:
a) access types supporting asymmetric/multimedia services, e.g. Video on Demand (if not part of B-ISDN access
types);
b) access types supporting broadcast services (if not part of B-ISDN access types);
c) access types supporting LAN interconnect functionality (if not part of B-ISDN access types);
d) access types that can be supported via an ATM VP cross-connect.
The concept of Virtual User Ports (VUP), as described EN 301 005-1 [14], may be applied to enable any specific
implementation.
In accordance with the principles of B-ISDN (as specified in ITU-T Recommendation I.121 [22]), remote access
arrangements across interfaces at the VB5.2 reference point shall support switched, and (semi-) permanent
point-to-point and point-to-multipoint connections. They provide on demand, reserved and permanent services of a
mono- and/or multi-media type and of a connectionless or connection-oriented nature in a bi-directional or
unidirectional configuration, as supported for direct access arrangements to service nodes.
Functions to support security management (refer to ITU-T Recommendation X.800 [62]) related to the customer access
are beyond the scope of the present document. Such security management functions have no impact on the VB5.2
reference point.
ETSI
13 ETSI EN 301 217-1 V1.2.2 (1999-09)
The present document does not specify the implementation of the requirements within the AN and does not constrain
any implementation alternative as long as the functionality at the interfaces at the VB5.2 reference point as specified in
the present document is met. Furthermore, the present document does not require that an AN shall support all the
customer access types listed above.
The present document is not intended to define any systems or equipment in, or connected to, an SN via interfaces at the
VB5.2 reference point. Therefore only the characteristics of the interfaces at the VB5.2 reference point are described.