Answering Incoming Calls; Speeds Of 128Kbps; Identifying Your Line Provisioning - ZyXEL Communications Omni TA128 User Manual

Chapter 7 - V.120 ISDN Communications
OK
All the above commands can be simplified by combining all of the commands onto one
line as follows:
AT&B20&E1&WZ0<Enter>
Dialing in V.120 mode
Finally, use the ATD n command to make the call (n is the phone number you wish to
dial). Once the connection is made, you should see the following connect message.
CONNECT 115200/V120 56000/LAPD
This indicates that the connection is made with:
DTE speed of 115,200bps
Protocol V.120
Data Speed 56,000bps
Error Control LAPD

Answering incoming calls

In most cases, there is no need to configure the Omni TA128 to properly answer calls.
The Omni TA128 is able to decide which protocol to use by detecting the type of data
that is coming in. All you need to do is set S0 to greater than or equal to 1, so the Omni
TA128 will automatically answer an incoming call. If S0=0, the DCE will simply report
"RING" to your terminal and sound a ring notification.
One exception to this is when the ISDN data call is carried through Speech bearer. In this
case, you would need to make an MSN entry for the phone number that you are
expecting the Data-over-Speech-bearer call to be coming for V.120 protocol. Use
AT&ZI2= n. Please refer to the section entitled "Data over Speech Channel" in Chapter 4
for details.

Speeds of 128Kbps

BRI ISDN consists of three (2B+D) logical channels. Each B channel can be used
independently for a dial-up connection running at 56Kbps or 64Kbps (bits per second).
The two B channels can be used together for a single data connection to provide 112K
(with In-Band Signaling) or 128K (when Out-of-Band Signaling is used). It is called a
"Bundle Connection" (different from BONDING).
The type of channel bundling described in the V.120 section is supported between two
ZyXEL Omni TA128's or Elite 2864I's only, and uses Multiple Link Protocol (MLP).
To make bundled connections to other ISDN TA's as well as ZyXEL TA's, refer to the
section entitled "Multilink PPP" in the preceding chapter.

Identifying your line provisioning

For bundled connections, the two B channels of your ISDN line must be able to handle
data circuit switch connections with unrestricted 64K or 56Kbps line speeds. Two
separate data calls will be established consecutively.
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