IBM SC30-3681-08 manual WAN Restoral Conguration, Channelized T1/E1, Isdn Configset switch chan

Using ISDN

WAN Restoral Con®guration

Figure 37 shows how you can use an ISDN connection to back up a failed dedicated WAN link (WAN restoral). In this example, Router A normally uses the WAN link to communicate with Router B. If that connection fails, the ISDN dial-up link reconnects the two routers. When the WAN link recovers, the secondary link automatically disconnects. For more information on how to con®gure the router for WAN restoral, see Using WAN Restoral in Using and Con®guring Features.

		WAN link
	I
Dial	S	ISDN
Circuit	D
		backup link
	N
Router A
		ISDN

Figure 37. Using ISDN for WAN Restoral

I

SDial

D Circuit

N

Router B

For WAN Restoral, only dial circuits con®gured for PPP can be used as the secondary link. For WAN Reroute, either a PPP dial circuit or a FR dial circuit can be used as the alternate link.

Channelized T1/E1

When con®gured for channelized, the Channelized/PRI adapter allows you to get Fractional/Channelized T1/J1/E1 support. You can have channels of 56-Kbps or N*64-Kbps. This will let you multiplex multiple leased lines connections (for example: using V.35 at 56-Kbps) into one physical connection.

To con®gure a T1 or E1 Primary adapter as channelized:

1.Select ªChannelizedº as the switch variant for the ISDN interface.

2.Con®gure the time slots to be used for this ISDN interface when you con®gure the dial circuit. See ªSetº on page 646 for more information.

Example of con®guring a Channelized T1 interface:

Config>n 6

ISDN Config>set switch chan

ISDN Config>list

ISDN Configuration

Maximum frame size in bytes		=	2048
Switch Variant/Service	Type	=	Channelized
Available Timeslots: 1	2 3 4 5 6 7		8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Config>n 7

Chapter 45. Using the ISDN Interface 617