Avaya Configuring Dial Services Manual do Utilizador descarregar pdf (Página 67)

Implementation Notes

3-17

Breath-of-Life Messages

When you conﬁgure primary circuits, Site Manager automatically enables Breath-

of-Life (BOFL) messages on each primary circuit and disables them on each

backup line. BOFL messages verify that the line is transmitting and receiving

data. With the exception of primary lines running Frame Relay, the router requires

BOFL messages to detect a failed primary line. (Frame Relay uses A-bit

notiﬁcation, as described in the next section.)

Site Manager conﬁgures BOFL messages through the BOFL parameter, which is

part of the synchronous line conﬁguration. For more information on this

parameter, see Conﬁguring Line Services.

Conﬁguring Primary Circuits for Frame Relay

If the primary circuit is a Frame Relay direct mode, permanent virtual circuit

(PVC), the Frame Relay service provider must support A-bit notiﬁcation. The

A-bit informs the router of the status of the virtual circuit, enabling the router to

back up the PVC if it fails. Without A-bit notiﬁcation, the remote end of the direct

mode PVC is never notiﬁed when the local-side PVC has terminated, making

backup support impossible.

Deﬁning the Role of the Router in the Network

When you conﬁgure a router for dial backup, you must specify whether the router

is to be a primary (master) router or a secondary (slave) router. The primary

router initiates the backup call when the primary circuit fails. The secondary

router waits for the call without trying to initiate it. If the primary/secondary

relationship does not exist, each router tries to call the other simultaneously, and

the routers receive busy signals.

You deﬁne the role of the router via the Backup Mode parameter, which is part of

the primary circuit conﬁguration (see Chapter 5). Do not conﬁgure both sides of

the circuit with the same value.

1 2 ... 62 63 64 65 66 67 68 69 70 71 72 ... 257 258

Sem comentários

Avaya Configuring Dial Services Manual do Utilizador Página 67