RMDB System



TECHNICAL OVERVIEW

The dial backup feature provides an inexpensive way to create redundancy for two offices of a CLIENT linked by Internetghana's clear channel data links in a WAN fashion using Cisco routers as the route discriminator and WAN/LAN integrator. This is achieved by allowing the designation of a router backup interface that stays idle until the primary clear channel data circuit is unavailable. When this condition occurs, the dial backup line is automatically activated until the primary link is restored.



How it works

When the main Clear channel data circuit between the two offices, namely the branch office and the Head office in Accra, goes down as a result of a problem in the last mile solution, the dial profile for the dial backup connectivity on the Cisco Router located at the branch office detects a lost Carrier Detect or line protocol down signal from the primary link.

The dial profile immediately activates DTR on the remote dial modem backup link. The Two-Port Analogue Modem WAN Interface Card dials simultaneously two analogue phone lines via the local PSTN to the Head office.

When the dial backup connection is made from the office to the Head Office, the routing protocol defined for the dial backup profile on the Router takes over the task of transmitting traffic to and from the Head office over the dial backup line until the primary Clear channel data circuit restores.