DVM Signaling Format (DVM Only)

The DVM Signaling Format parameter is used to match the signaling format of the digital voice port to the interfacing PBX. The following options are available:

• Tie Trunk (for T1 and E1)*
• Tie Invert (for T1 and E1)
• Clear Channel (for T1 and E1)
• DC5B (for E1 only)*
• Inverted DC5B (for E1 only)
• R2/PUNCOM (for E1 only)
• R2/Q.421 (for E1 only)*
• Israel CAS (for E1 only)
• Spain CAS (for E1 only)
• Wink Start (for T1 and E1)

*Not currently implemented.

Tie Trunk

For tieTrunk, signaling bit A defines the on-hook/off-hook conditions as shown below. Signaling bits B, C, and D are denoted by "X", a "don't care" condition.

Use this option when the interfacing PBX follows Tie Trunk Channel Associated Signaling (CAS) protocol emulation established by the International Telecommunications Union (ITU).

Tie Invert

For tieInvert, signaling bit A defines the on-hook/off-hook conditions as shown below. Signaling bits B, C, and D are denoted by "X", a "don't care" condition.

Use this option when the interfacing PBX follows Tie Invert CAS protocol emulation established by the International Telecommunications Union.

Clear Channel

When clearChannel is selected the voice path in the channel is open all the time, independent of the signaling bits or tones present in the channel. In this case, link bandwidth assignment is based on the presence or absence of audio signals (voice/fax) when Voice Activated is the selected Bandwidth option.

Select this signaling format when using Transparent CCS. See Transparent CCS for details.

DC5B

For dc5B,signaling bits A, B, C, and D define the on-hook/off-hook conditions as follows:

Use this option when the interfacing PBX follows DC5B CAS protocol emulation established by the International Telecommunications Union.

Inverted DC5B

For dc5bInvert, signaling bits A, B, C, and D define the on-hook/off-hook conditions as follows:

Use this option when the interfacing PBX follows inverted DC5B CAS protocol emulation established by the International Telecommunications Union.

R2/PUNCOM

For r2PUNCOM, signaling bits A, B, C, and D define the on-hook/off-hook conditions as follows:

Use this option when the interfacing PBX follows R2 Puncom CAS protocol emulation established by the International Telecommunications Union.

R2/Q.421

For r2Q421, signaling bits A, B, C, and D define the on-hook/off-hook states as follows:

Use this option when the interfacing PBX follows R2/Q.421 CAS protocol emulation established by the International Telecommunications Union.

Israel CAS

For israelCAS, signaling bits A, B, C, and D define the on-hook/off-hook states as follows:

Use this option when the interfacing PBX follows IsraelCAS Protocol emulation established by the International Telecommunications Union.

Spain CAS

For spainCAS, signaling bits A, B, C, and D define the on-hook/off-hook states as follows:

Use this option when the interfacing PBX follows SpainCAS Protocol emulation established by Telefonica Spain.

Wink Start

When CAS signaling format winkStart is selected, signaling bit A defines the on-hook/off-hook conditions as follows (signaling bits B, C, and D are denoted by "x", a "don't care condition".

Wink Start Operation

In the example shown below, a local user connected to a digital PBX attempts to reach a user connected to a remote digital PBX at station 56. Each PBX trunk is attached to a T1/E1 digital voice module (referred to as a channel in subsequent discussions) housed within a Passport 4430/50/55 unit. Connection between the two voice channels may be established over the switched network.

It is assumed that the network extension number of the remote voice channel is 1234. It is further assumed that both voice channels are configured for the winkStart DVM signaling format, and that local and remote ingress/egress tables and their respective manipulation strings are properly configured.

Following is a sequence of events involved in establishing a connection between the two users:

1. The local user dials 123456.
2. The local PBX stores digits 123456, and seizes the time slot by switching signaling bit A from 0 to 1. (See table in Wink Start)
3. After a minimum of 100 milliseconds, the local voice channel (DVM) responds with a wink signal ranging from 140 to 290 milliseconds (200 ms nominal), then returns a dial tone.
4. The local PBX forwards digits 123456 to the local DVM.
5. The local DVM uses digits 1234 to establish a connection with the remote voice channel, and forwards digits 123456.
6. With connection between the local and remote voice channels established,
   the remote voice channel goes off-hook to the remote PBX, and starts a pre configured regeneration time delay. See Delay (High Regeneration).
7. Shortly after 100 milliseconds, and before the time delay expires, the remote PBX returns a wink signal to the remote voice channel. This signal is ignored by the remote voice channel. When the time delay expires, the remote voice channel regenerates digits 56 in either dial pulse or DTMF, based on the format configured for that channel. Using the regenerated digits, the PBX rings station 56. Connection is established when the user at station 56 answers.