Well, a little while ago, I decided that I'd play around with Carrier
Access Codes (CACs) and some other miscellania in my area. All of this
information is relative to western Canada, primarily 780 and 403
(Alberta), and 250, 604 and 778 (British Columbia). The information
about what can be done in my area is relative to Edmonton, Alberta.
A little background on a few CACs.
1010324 was Telus' primary CAC for the Edmonton area, and most of
Alberta, before the merger with BCTEL. Now, 1010323 is Telus' primary
CAC, so 1010323-0 will give you an operator, and 1010324-00 will give
you a long distance operator. The 1010324-0 simply gives you a fast
busy. Same with 1010324-00. So if you sign up for normal Telus long
distance, you'll get 1010323 as your CAC. I don't beleive that Telus
has any additional casual-use charges for use of their CAC.
1010424 was BCTEL's primary CAC for it's areas of control in BC,
before the merger with Telus. Post-merger, 1010424 became a "special
services" CAC. In other words, 1010424 was used for people that
required special billing or special features of some sort. 1010424 has
varied accessibility in different areas of Canada. It's accessible
from Edmonton, but that is all that I can verify at this time. I'll
explain what I consider "accessible" to be later on.
A few other carriers also have CACs that are accessible from Edmonton
and surrounding areas, for example Primus (1010615), Bell Canada
(1010363), and Sprint (1010348).
A Carrier Access Code is a code that enables you to select which long
distance provider you want to handle your calls. For example, if I
sign up for Telus long distance. Let's say that I want to call my
friend "Chris" in Massachusetts (NPA 413). Telus long distance might
be 9 cents a minute, anywhere in Canada and the USA. But, let's say
that Sprint has a special rate of 5 cents a minute to
Massachusetts. I'd rather use the Sprint carrier. So, instead of
dialing the number as I normally would (1-413-445-6666), I would
prefix the number with the Carrier Access Code. This would yeild,
"1010348-1-413-445-6666." Dialing this number would route my call over
Sprint's long distance network for this call only. Dialing in this way
(with the CAC prefixed before your number) is referred to as "Casual
Use." Interexchange carriers are will often charge casual-use calls at
a higher rate than the posted long-distance prices. It is best to
verify the casual use rates (if any) with your IXC before using CACs.
Anyway, on to the specific behaviour of CACs. Prefixing your call
with a CAC and calling a toll number often results in very different
behaviour than simply direct dialing a toll number. Often, dialing
through CACs yeild many restrictions that are not present when direct
dialing numbers, such as restrictions on 900-number dialing,
800/888/877/866 toll-free number dialing, 950-XXXX (Feature Group B)
dialing, 700-number dialing, and many other restrictions. Often,
attempting to dial a local number through a CAC will yeild a
Cannot-Be-Completed-As-Dialed (CBCAD) error, or simply a
fast-busy. This is expecially evident in many parts of the USA and
Eastern Canada. However, when dialing local numbers through CACs in
Edmonton and many other parts of Western Canada, the restrictions are
slightly different. I will explain the behaviour below.
For those readers that are not familier, Telus has a very lax system,
when it comes to dialing formatting for local numbers. Any of the
following will complete properly, and charge as a local call:
958-6111
780-958-6111
1-780-958-6111
So you can see there is a lot of flexibility on how you want to dial
your local calls. Both 958-6111 and 780-958-6111 will terminate
normally, and ring the party after you've finished
dialing. 1-780-958-6111, however, will play a message that states,
"Your local call is proceeding. There is no need to dial long
distance. Thank you, from Telus," before completing your call
(assuming you called a number that terminated properly, and didn't
intercept, or do something weird).
All CACs in my area have fairly standard behaviour when it comes to
dialing local numbers. Also, this behaviour is quite different than
normal direct-dialing. Normally, you dial the whole number as one
string, and the entire string is parsed at once. However, certain CACs
can be made to match at the thousands block, instead of waiting for
the entire string to be dialed. The situations that will cause a CAC
to match at the thousands block are as follows. Note that it is
assumed that the conditions below are prefixed with a CAC. Note that
these are also general situations, there are specific situations that
can cause other specific intercepts, those will be listed and
explained later.
1. Dialing a local number that is in the same exchange (NXX) as you.
For example, if my number was "780-444-5555", and I dialed,
"1010424-1-780-444-5556", my pattern would be matched at the thousands
block (which is the first "5", in case you weren't aware), and will
immediately intercept. The exact intercept it gives is discussed
later.
2. Dialing a local number that is outside of the city you live in.
For example, if I lived in Edmonton, and I dialed an exchange in
Sherwood Park (which is just outside of Edmonton), such as 464, it
would again, intercept at the thousands block. Sherwood Park is
normally a local call when direct dialed.
3. Dialing a cellular prefix within your city.
For example, if "903" is a cellular prefix in Edmonton, then
dialing "1010424-1-780-906-6" will intercept after I dial the
thousands block (the last "6"), before I can finish entering the
number.
All of these conditions will give the same intercept. As soon as you
finish dialing the the thousands block, it will ring for a certain
amount of time, then the call will intercept to a recording of "Your
local call is proceeding. There is no need to dial long
distance. Thank you, from Telus." Then, you'll hear a quarter-second
snippet of some other intercept recording on the switch (which is a
documented DMS bug that has never been fixed, likely because it occurs
so rarely, and isn't really an annoyance). Following the snippet, you
will hear ringing. You will then hear an intercept message.
Note that the intercept message can sometimes come on *before* the
ringing, and the ringing will be heard overlayed on the error
message. The error message states, "The number you have called cannot
be completed as dialed. Please check the area code and number before
trying again, or dial 411 for directory assistance." This error will
repeat three times, and on the third time, it will but off before it
can get to the word, "assistance." Also note that dialing a local
number prefixed with a CAC doesn't actually go through the CAC. So,
even though you might not have Bell Canada long distance, you can
still dial a local number (subject to the previous requirements)
prefixed with a CAC.
A bit more on local calling through CACs. I wanted to get another
viewpoint on this interesting situation, so I called up the Telus
Network Operations Center, and talked to a fellow in DMS Switching,
Jason. He was on break, but he took some time to talk to me, which I
really appreciate. When I explain what I had encountered with not
being able to call cellular numbers, or out-of-city numbers through
any CACs, he noted a few things that he thought might cause that. He
mentioned that it was possible that the switches would not route
*local* calls prefixed with a CAC from tandem to tandem, but would
only route them from tandem to end-offices. So, any end-offices not
directly connected to the tandem would not be able to be contacted,
and he speculated that was why only calls within the city of Edmonton
could be made through the CACs.
Of course, this was speculation, and it would be appreciated if
someone outside of Edmonton could verify that you really can, only
call numbers in your city. I also discussed the issue of not being
able to call numbers on your own exchange with Jason, he attributed it
to switch programming as well, but neither of us were aware of any
particular hardware restriction or regulation that would require it to
be so. By all rights, it should work. Either way, thanks Jason for the
comments!
Alright, a bit more on 1010424. As I previously stated, 1010424 is a
CAC that is now used for "special services." Not every regular casual
caller can use all the features on the line. Some of the following
conditions will cause 1010424 to tell you, "We're sorry, you are not
authorized to call the number dialed."
1. Dialing a Feature Group 'B' number
ex: 1010424-1-780-950-8888
2. Dialing 1010424-0 (operator)
3. Dialing 1010424-00 (long distance operator)
4. Dialing any long-distance number
ex: 1010424-1-604-477-1452. Note that it doesn't matter if the number
supervises or not, it still intercepts to that message.
5. Dialing 1-780-555-1212
This illustrates where 1010424 contrasts with 1010323. All of the
previous stated conditions are conditions that would require the
"special billing" parts of the system to be activated. Simply dialing
local calls, within your own city, and not on your own switch,
however, are local calls, and like most of Telus-land, free. So the
"special billing" stuff never has to get activated. Also note, you can
still dial 1-700-555-4141 and it'll tell you that "Telus" is your
long-distance carrier. So if you want to verify that this is a valid
CAC for Telus, you can, right like that.
Alright, a bit more about 1010323. 1010323 is the normal Telus CAC,
and you can place calls normally through it. 1010323-0 yeilds you an
operator, 1010323-00 gets you a long-distance operator. You can place
long-distance calls normally, and "special" stuff like Directory
Assistance (1-NPA-555-1212) works normally, and when you dial through
and place local calls, with the restrictions I listed above on local
calls.
Alright, a bit more on some other CACs. Bell Canada's CAC is 1010363,
and it's quite similar to Telus' 1010323, with a few notable
differences. You can't call an operator (via either 1010363-0 or
1010363-00) through Bell's CAC, at least, I've never gotten one. It
might be possible to get an operator if you are subscribed to the
service, but I've never gotten one. Comments, anyone? Also, if you
dial up 1010363-1-700-555-4141, you'll get a nice messages telling you
that Bell Canada is your long distance provider. Trying to make a
normal long distance call, though, will net you the message, "We're
sorry, the service you are calling cannot be reached by this method."
Primus also runs 1010615, which is entirely unremarkable, except for
1010615-0, which will get you an automated attendant. I'm not sure if
Primus has any additional casual-use charges. Telus' old CAC, 1010324,
will intercept with the message, "This service is no longer available
in your area. We apologize for the inconvenience," no matter what you
try to call. Sprint runs a CAC as well, 1010348, which is again,
entirely unremarkable.
That's about it. Comments, anyone? Does it work like this in anyone
else's area?
-Tim
Tim Scott (othtim@gmail.com)