Telos NX12 - Manual (Page 20)

10 | section 2
2.6 Integration with a PBX
The Nx12 will usually be used independently of any other phone system in your facility. But it is
possible to have one or more of the lines come off another phone system. Depending upon the
PBX and your preferences, this can be either ISDN BRI or POTS.
You might be able to save money by using a T1/E1 or ISDN PRI as your Telco link and having
the PBX generate local ISDN BRI or POTS lines for the Nx12.
Consider having at least one line directly from the Telco to keep your Nx12 up and running
even if the PBX or its Telco connection goes down.
Using ISDN
Telos equipment has been used satisfactorily using BRI off the following PBX Switches:
USA and Canada
Nortel Meridian Option 11, 2 wire (U interface). Protocol ID = 6. [user report]
♦
Lucent/Avaya Definity, 2 wire (U interface) [user report]
♦
Avaya IP Office (must use Q.931 mu setting on Telos) [user report]
♦
Outside of the USA
Siemens HiCom series, 4 wire (S interface) [user report]
♦
ETS300 Euro-ISDN is available from many PBX systems outside the USA and compatibility
is generally good.
Unless your PBX is listed above, its support of US/Canada National ISDN-1 is not certain. We
recommend you arrange a test for compatibility before committing to the purchase of the PBX
ISDN module.
Contact Telos support for the latest information, or to report your experiences with other
switches.
Using POTS
Most PBX or VoIP telephone systems can provide analog ports for analog equipment such as
modems and fax machines. You will need such ports to connect a POTS Nx12 to a PBX.
With all calls passing through the PBX, calls into the main station number can be transferred
over to the on-air system. If the PBX supports ‘hook flash transfer’ on the analog ports, you can
even use this feature of the Nx12 to transfer lines from the on-air system back to the PBX. This
can also be done if the PBX and Nx12 share Centrex lines.
A few years ago, we advised that hybrid performance was best when equipment was connected
directly to the lines from the Telco. Today, this is not always true. If the PBX is connected to the
Telco using digital lines (such as T1, E1, PRI, S2M, etc), performance through a digital PBX
will generally be better than direct connections to copper analog circuits. This is particularly so if
you are located a significant distance from the Telco central office.
The biggest variable when connecting to a PBX analog port is the quality of the analog port. We
have found that many PBX manufacturers offer more than one analog port option. The better
port can usually be distinguished by its higher cost, and the fact that it may offer 48 volts rather
than 24 volts. The Nx12 will work with either voltage; however experience has shown that the
48-volt version usually has better quality transformers and other components, resulting in better
hybrid performance.