Ubigate iBG1000 System Description/Ed.02
© SAMSUNG Electronics Co., Ltd.
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(Continued)
WAN Protocols
Descriptions
ISDN
WAN interfaces are connected typically using leased lines such
as T1/E1, but there are chances that the T1/E1 links goes down
due to various reasons thereby resulting in the loss of wan
connectivity. The wan connectivity comes up only when the
T1/E1 links are restored. Hence there is a need to have an
alternate connectivity till the T1/E1 links are restored.
When the primary connectivity (T1/E1) links go down, ISDN can
be used as a secondary connection. ISDN can be used as a dial
up connection to connect to Internet or a remote server for
certain amount of time until the primary T1/E1 links are restored.
ISDN can also exist as an independent interface to provide
remote connectivity to Headquarters and/or for Internet
connectivity in a very similar way to the other interfaces like
T1/E1. In certain countries the ISDN connections are not so
expensive that they can be used as the primary connections as
well. ISDN PRI is also supported via T1 and E1 interfaces.
