19
Exchange interfaces and tasks, V2-V4
nV2:
Interface serves typically concentrators
n2048 kbit/s
eg
n30 B + D
nElectrical
standard G.704
nV3:
Resembles V2 but intended for interface other exchanges
(PABX)
nElectrical
standard
n30 B + D at
2048 kb/s
nalso 23 B
+D at 1544 kb/s (I.431)
nV4:Interface
to private networks (not ITU-T specified), for instance DSLAM
(ADSL-interface)