From: varney@ihlpf.att.com (Alan L Varney)
Newsgroups: comp.dcom.telecom
Subject: Re: Dial a #, Connect Quicker?
Date: 21 Aug 92 21:42:42 GMT
Organization: AT&T Network Systems, Lisle, IL
X-Submissions-To: telecom@eecs.nwu.edu
X-Administrivia-To: telecom-request@eecs.nwu.edu
X-Telecom-Digest: Volume 12, Issue 652, Message 13 of 13

In article <telecom12.640.8@eecs.nwu.edu> jhenderson@pomona.claremont.
edu writes:

> On a dialing instructions booklet I received from AT&T recently, it
> suggests to dial a # after the last digit on international calls, so
> the call can be completed quicker.

> Since then, I've been dialing a # after the last digit on all my long
> distance calls, both domestic and international, and they all seem to
> complete faster.  Is this just my imagination, or is the # really
> helping? My LD company is MetroMedia, in case it makes a difference (I
> have no idea why AT&T sent me the booklet, they've never been my LD
> carrier.)

   I can't speak for MetroMedia, but Bellcore's recommendation is that
all Country Codes (other than "1") be treated as variable-length,
since they no longer want to bother sending out the updates every time
CCITT decides to alter the fixed length of some country's numbers.  It
was a hassle to administer after divestiture, and getting it "wrong"
leads to a lot of customer complaints.  So (I believe) they are all
set for the maximum range (7-to-12)? of valid CCITT numbers.  So, yes,
use "#" on International calls to stop the digit timing that otherwise
occurs -- unless the number is already 12 digits.  Note that "#" can
do funny things to some phones (that change from pulse-to-DTMF on "#"
or "*") and could have other meanings for some other CPE, such as
PBXs.

   If MetroMedia is using FG-B access or 10XXX# cut-through, digit
timing is up to them (or the real carrier acting for them, if that
applies).  If the CO is collecting all the digits and using FG-D
access, the digits are timed at the CO and sent to the IXC with MF,
terminated with an 'ST' digit.  In most COs, a '#' on a domestic "1+"
call is ignored by the CO, because it already knows it's received the
last digit and has dropped the DTMF receiver.

> [Moderator's Note: In Metromedia's case, I think pounding off in the
> middle of a call will reset the dial tone for you, and allow another
> call to be dialed. At least that's my experience with that carrier. I
> think maybe AT&T allows this also on calling card calls, no?  In the
> dialing sequence, the # acts like a carriage return and forces the
> processing to begin on what has already been dialed without waiting
> for a timeout.

   "#" does speed up processing here -- maybe digit analysis doesn't
get the digits until the Operator system has collected all the digits,
either by time-out or "#".

> I don't think it makes any difference with domestic calls since 11
> digits is expected and you have entered that many when you pound off.

> It also matters on the few variable-length dialing situations we
> have in the USA; Likewise, service codes like 72 and 73 process faster
> with the # appended, but will work without it.  PAT]

   (From memory -- I'm not at work ...)  The evolution of Custom
Calling access started with two-digit codes, followed by "#" to end
timing.  The number space for these included the "7X" codes for
feature access, plus the "X" (X=2-9) and "NX" (N=2-4 & X=0-9).  The
two-digit codes on either side of the "7X" area were reserved.  And,
of course, Centrex was different, because of prior usage of "9" and
"8".

   The next wave of planning recognized that the original Custom
Calling features might be only a start, and changed to a "*XX" form of
access.  Speed Calling didn't change, so "#" was still useful there.
Backward compatibility forced "72#", etc. to still be accepted, and
required that "11XX" would serve as "*XX" for the (still-majority)
telephones.  Neither the "*" nor "11" form require timing for more
digits, so "*72#" isn't helpful.

   Divestiture allowed Bellcore (with a lot of old Bell System folks)
to re-examine the Access-to-Features issue.  Thus "#XX" for service
access and "*XX" for feature access (or maybe the reverse).  Anyway,
"#56" became the Switched-56 access code, and "#XX" was reserved for
others.  No dial-pulse equivalent was chosen.  And most new features
only briefly, if at all, mention "11XX" as an alternative to "*XX".
Some areas/vendors don't support the older "72#" form, and others
don't yet support the "*72" form.

   Bellcore is attempting to mine a few more feature codes by using
the form "*1XX" and "*0XX" to add about 200 more codes.  I haven't
seen any mention of "111XX" being permitted.  By the time they
exhaust, they hope to have something even better for feature access --
maybe a multi-level menu with prompts!!


Al Varney  -- just MY opinion