In addition to the voice signals that are sent to and from the caller, other signaling information is also sent to and from the switch, to enable such functions as:
A variety of signaling protocols provide some or all of these functions. Functions that are supported by T1 protocols are listed in Table 1, and functions that are supported by E1 protocols are listed in Table 2. Before deciding on or configuring a specific protocol, you must ensure that your central office switch, PSTN, PABX, or channel bank can also support the required functions. More information about the protocols is given in the Blueworx Voice Response for AIX: General Information and Planning information.
Protocol |
Type 9 |
Connectivity |
Function |
||||||
---|---|---|---|---|---|---|---|---|---|
PSTN |
PABX |
Channel bank |
Answer detection |
Call transfer |
Far-end disconnect |
ANI |
DID or DNIS |
||
E&M1 |
Trunk |
Yes |
Yes |
Yes2 |
Yes |
No3 |
Yes |
Yes |
Yes |
FXS Loop Start 1 |
Line |
Yes |
Yes |
Yes2 |
No |
Yes |
No4 |
No5 |
No 5 |
SAS Loop Start |
Line |
Yes |
Yes |
Yes |
No |
Yes |
No4 |
No5 |
No 5 |
FXS Ground Start 1 |
Line |
Yes |
Yes |
Yes 2 |
No |
Yes |
Yes |
No 5 |
No 5 |
ISDN (5ESS 5E9) |
Trunk |
Yes |
No |
Yes6 |
Yes |
No |
Yes |
Yes |
Yes |
ISDN (5ESS 5E12) |
Trunk |
Yes |
No |
Yes6 |
Yes |
No |
Yes |
Yes |
Yes |
ISDN (T1 National 2) |
Trunk |
Yes |
No |
Yes6 |
Yes |
No |
Yes |
Yes |
Yes |
ISDN (DMS100 BCS34/36) |
Trunk |
Yes |
No |
Yes6 |
Yes |
No |
Yes |
Yes |
Yes |
ISDN (TR41449/41459) |
Trunk |
No |
Yes |
Yes 6 |
Yes |
No |
Yes |
Yes |
Yes |
ISDN NA008 (DMS National)7 |
Trunk |
Yes |
No |
Yes6 |
Yes |
No |
Yes |
Yes |
Yes |
ISDN IEC05 (DMS250)8 |
Trunk |
Yes |
No |
Yes6 |
Yes |
No |
Yes |
Yes |
Yes |
ISDN(INS Net Service 1500) |
Trunk |
No |
Yes |
Yes6 |
Yes |
No |
Yes |
Yes |
Yes |
In the Type column, Trunk means “trunk-side protocol” and Line means “line-side protocol” Note:
|
Protocol |
Type12 |
Connectivity |
Function |
||||||
---|---|---|---|---|---|---|---|---|---|
PSTN |
PABX |
Channel bank |
Answer detection |
Call transfer |
Far-end disconnect |
ANI |
DID or DNIS |
||
E&M1 |
Trunk |
Yes |
Yes |
Yes |
Yes |
No2 |
Yes |
Yes |
Yes |
FXS Loop Start |
Line |
Yes |
Yes |
Yes |
No |
Yes |
No3 |
No4 |
No4 |
EL7/CAS |
Line |
No |
Yes5 |
No |
Yes |
Yes |
Yes |
No6 |
No6 |
Italy |
Trunk |
Yes |
No |
No |
Yes |
No |
Yes |
No |
Yes |
R27 |
Trunk |
Yes |
Yes |
Yes |
Yes |
No |
Yes |
Yes |
Yes |
R2MFC8, 9 |
Trunk |
Yes |
No |
No |
Yes |
No |
Yes |
Yes |
Yes |
RE |
Line |
No |
No |
Yes |
No |
Yes |
No |
No |
No |
SL10 |
Line |
Yes |
No |
No |
Yes |
No |
Yes |
No |
No |
TS00311 |
Trunk |
Yes |
Yes |
Yes |
Yes |
No |
Yes |
Yes |
Yes |
UK Callstream |
Trunk |
Yes |
No |
No |
Yes |
No12 |
Yes |
No |
No |
UK Exchange |
Trunk |
Yes |
No |
No |
Yes |
No |
Yes |
No |
No |
UK Tie/DDI |
Trunk |
Yes |
No |
No13 |
Yes |
No12 |
Yes |
Yes |
Yes |
ISDN |
Trunk |
Yes |
Yes |
No |
Yes |
No |
Yes |
Yes |
Yes |
SS7 ISUP |
Trunk |
Yes |
No |
No |
Yes |
No |
Yes |
Yes |
Yes |
In the Type column, Trunk means “trunk-side protocol” and Line means “line-side protocol” Note:
|
Two classes of signaling protocol exist: channel associated signaling (CAS) and common channel signaling (CCS). In addition, an exchange data link (EDL) can be used with a CAS protocol to provide additional signaling functions.
When channel associated signaling protocols, such as E&M wink start, or FXS loop start, carry the signaling information for a particular channel, they carry the information on either of the following:
This signaling information enables call control (call setup and clearing), but other functions, such as far-end hang up detection, are not necessarily provided by all channel associated signaling protocols.
If your CAS protocol does not provide all the signaling functions that you need, you might be able to use an exchange data link; that is, a link from the switch to the pSeries computer on which Blueworx Voice Response runs. This link can carry additional signaling information to enable:
Exchange data link signaling protocols, such as ACL, SMDI, SMSI, and VMS, are typically used with trunks that use a channel associated signaling protocol for call control.
Alternatively, you can use CallPath Server to send additional information to and from the switch, including called and calling number, message waiting indication (MWI), and far-end hangup detection. The CallPath_SigProc signaling process that is used to communicate with CallPath Server is registered as an exchange data link, and needs to be configured in a similar way.
Common channel signaling protocols, such as Signaling System Number 7 (SS7) and Primary Rate Integrated Services Digital Network (ISDN), carry allthe signaling information for many voice channels over a single, dedicated signaling link. The common channel signaling link can provide:
The signaling link is usually one 64 Kbps channel on a T1 or E1 trunk. Most common channel signaling protocols are based on the OSI reference model (X.200), and work by exchanging predefined messages.