Black Box IS425A, Manual, Page: 80 / 107

IS425A - ISDN Terminal Adapter with S/T-Interface
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10.2 Suggested Ordering Codes
IS425A (alone) – The IS425A uses both Voice and Data, and can access
a variety of the voice capabilities that make ISDN valuable. To
use this value, your must decide how to provision your line to get
the best value from the telephone company.
These are the voice options you should consider:
1.
Basic Voice (Caller ID only) -- Code “S”, and see the ACO
note just below.
2. Supplementary Services (Call Waiting, Hold, Conference,
Transfer, and Drop). You may opt for ordering “S” plus any
or all of these services. – “P”, “Q”, “U” or “V” (READ
ON!)
Here’s where things get complicated. On some switches, there is
a feature called CACH/EKTS. Using CACH/EKTS is better and
easier, but is sometimes more expensive. It is also sometimes
unnecessary; you only need CACH/EKTS if you want more than
basic voice services. Bottom Line – if it doesn’t cost anything
more, get CACH/EKTS; and if it does, decide if it’s worth it for
you. In general, it is recommended that you get CACH/EKTS if
possible.
NOTE: If you cannot or do not get CACH/EKTS, it is important that
you order Additional Call Offering (ACO) feature. This allows
the IS425A to allow a 128Kbps call to drop to 64Kbps for
incoming voice calls. Of course, if you do not want this feature,
do not order it.
For the IS425A alone , the recommended package for full usage is
“V”; however, “V” is usually the most expensive. It may or may
not be cheaper to order “S” and add the specific features you
want.
AO/DI or PADs – Some equipment makes use of the D-Channel for low
bandwidth data transfers. If are going to use these devices, or
you are going to use a device that supports Always On/Dynamic
ISDN (AO/DI), you may want to provision the line with D-
Channel Packet, or X.25, capabilities. – “P” or “Q”
“P” and “Q” also include supplementary services with most
Telephone Companies, so these features may not have to be
provisioned separately. The difference between “P” and “Q” is
that “Q” has CACH/EKTS provisioning. Again, you must decide
if you want CACH/EKTS, but it is recommended.