[asterisk-biz] What is DID? (answer)

[Jay R. Ashworth]

On Sat, Oct 07, 2006 at 01:52:00PM +0800, Andy Spring wrote:
>    What is DIDs, is it DIGITAL IMAGE DATA? could you kindly tell me some
>    details about this product, i am not familar with this device but want to
>    know very much

Should I answer, guys?

Or should I say "we don't do people's homework assignments for them;
UTFW"?  :-)

DID = Direct Inward Dial; a name for a flavor of trunk (group)
(equivalent service) which provides to the customer PBX/switch
information about which of several Directory Numbers which terminate on
that trunk group a given call was directed to.

Older DID's, either on T-1 or specially provisioned analog trunks, used
3 or 4 DTMF tones after wink and before pickup to send this
information; newer ones are usually ISDN PRI's and send it in the ISDN
User Part on the D channel.

It's also possible, I'm pretty sure, to receive DID information from a
PSTN-attached carrier via SIP on incoming calls.

Cheers,
-- jra
-- 
Jay R. Ashworth                                                jra at baylink.com
Designer                          Baylink                             RFC 2100
Ashworth & Associates        The Things I Think                        '87 e24
St Petersburg FL USA      http://baylink.pitas.com             +1 727 647 1274

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