ISDN Standards Overview 1 General Datacomm General Datacomm E Series protocols Telephone network standards such as E.164 for international addressing etc. I Series protocols Concepts, terminology and general methods such as I.200 services etc. Q Series protocols Switching and signaling standards such as; Q.921 describes data-link LAPD Q.931 describes network layer KCC 18th August 2002

General Datacomm General Datacomm PRI STANDARDS In USA and Japan T1/DS1 23 x 64kbps bearer (B) channels 1 x 64kbps data (D) channel In UK Australia & Europe 30 x 64kbps (B) channels 1 x 64 kbps (D) channel H channels bond multiple B channels BRI STANDARDS Most countries now 64kbps few remain on 56kbps 2 x 64kbps (B) channels 1 x 16kbps (D) channel KCC 18th August 2002 ISDN Standards Overview 2

General Datacomm General Datacomm KCC 18th August 2002 ISDN Example Topologies BRI S/T BRI U V.35 serial R V.24 serial R BRI S BRI S BRI T BRI U I S D N BRI U EXAMPLE SITE IN USA Local-Loop (U interface) available direct into the Router without the need for external NT1 EXAMPLE SITE IN EUROPE/UK Routers have BRI S/T interface and connect Into Telco supplied NT1 EXAMPLE OF LARGER SITE IN EUROPE/UK Routers can connect via NT1 or via NT2 using the BRI S/T interface Or any serial device can connect through a TA TE2 TE1 TA NT2 NT1 TE1 with NT1 built in

ISDN BRI startup sequence General Datacomm General Datacomm KCC 18th August 2002 Line inactive TE becomes active and signals a 7E HDLC flag (7E = “ ”) Network switch send frame with the A-bit set to 0 (A=0 = no activated) TE then synchronises on three successive pairs of line code voilations TE then starts sending physical frames NT synchronises using line code violations NT starts sending frames with A-bit set to 1 (A=1 = activated)

General Datacomm BRI S/T Interface (RJ-45) Pinouts RJ-45 pinTENTPolarity 3TransmitReceive+ 4 Transmit+ 5ReceiveTransmit- 6 Receive- BRI U Interface (RJ-45-to-RJ-45) Pinouts NT RJ-45WireLT RJ-45 4Tip4 5Ring5 KCC 18th August 2002 ISDN Physical