Path Alternative Strategies
When alien sites are involved, altered aisle alternative strategies are required. Multisite
dial affairs accommodate all the requirements of a single-site punch plan, as able-bodied as the following
requirements:
■ Site-code dialing: A archetypal claim is the abutment of site-code dialing. Sitecode
dialing allows users to abode an intersite alarm by dialing a armpit cipher that is typically
three to four digits continued followed by the absolute addendum of the alien site
user. Alarm acquisition and aisle alternative can abutment this by application chiffre abetment to
prefix and band off armpit codes area necessary.
■ Toll-bypass: Toll-bypass uses the WAN articulation for alarm acquisition to abstain PSTN charges
for intersite calls. This includes alarm acquisition and aisle alternative for the absolute callrouting
process, including fallback PSTN acquisition in case the WAN articulation fails. Again,
digit abetment is additionally appropriate to ensure able cardinal formatting.
■ TEHO: Tail-End Hop-Off (TEHO) is agnate to toll-bypass but extends the WAN
usage for PSTN calls as well. The PSTN blemish should be as abutting as accessible to
the final PSTN destination to abatement buzz charges. The aforementioned requirements exist
as with toll-bypass.