76.1. ISDN lines

76.1. ISDN lines
	Chapter 76. FAQ - Frequently Asked Questions

76.1.1. How can I verify if an ISDN line is active?

In ISDN PP lines, the physical layer must be ALWAYS active.

Type the command d d ctip:xx (where xx refers to the port that you want to check) and verify if the physical and logical layer are active:

Physical layer active:
- For PRI lines: ISDN-STATE:PRI-UP;
- For BRI lines: ISDN-STATE:F7-READY.
Logical layer Q.931 active: TEI=0 and STATE:07-CONNECTED.

For example:

[10:00:21] ABILIS_CPX:d d ctip:3

CTIP:3   ----------------------------------------------------------------------
       OPSTATE:UP          STATE:UP
       ------------------------------------------------------------------------
       CH: STATE: [Q932-STATE:] CG: [SCG:]              CD: [SCD:]
       ------------------------------------------------------------------------
       1   10-CONNECTED-TO      039997335               3419985005
       - Sapi ------- TEI -- STATE --------------------------------------------
         16 (X.25 )    10    00-INACTIVE
         0  (Q.931)     0    07-CONNECTED
       ------------------------------------------------------------------------
       ISDN-STATE:PRI-UP                  LINE-DOWN:27         SLIPS:8
       RxAlarms:NONE                      TxAlarms:NONE

In ISDN MP lines the physical layer is active ONLY when there is a current call; so if the physical layer isn't active, you cannot verify if the line is correctly working.

Type the command d d ctip:xx (where xx refers to the port that you want to check) and verify if the physical and logical layer are active:

Physical layer active:
- for BRI lines: ISDN-STATE:F7-READY.
Logical layer Q.931 active: TEI>=64 and STATE:07-CONNECTED.

For example:

[10:00:21] ABILIS_CPX:d d ctip:33

CTIP:33   ----------------------------------------------------------------------
       OPSTATE:UP          STATE:UP
       ------------------------------------------------------------------------
       CH: STATE: [Q932-STATE:] CG: [SCG:]              CD: [SCD:]
       ------------------------------------------------------------------------
       2   10-CONNECTED-FROM    3401233729              172695572
       - Sapi ------- TEI -- STATE --------------------------------------------
         16 (X.25 )    10    00-INACTIVE
         0  (Q.931)    64    07-CONNECTED
       ------------------------------------------------------------------------
       ISDN-STATE:F7-READY                LINE-DOWN:27         SLIPS:8

76.1.2. Back up over ISDN doesn't work

The most frequent cause of backup ISDN isn't working is the configuration SGI:* in a resource over B-channel or a resource with backup, that could intercept backup calls.

You must verify that there are no resources (X25, IP-BCK, AIPT-BCK,etc) with SGI:* and eventually, to insert the correct value or SGI:disabled.

Tip

	Tip
With the d d ctislink command, it's possible to display the resources (with their `SGI` value) ready to receive a connection over the B-channel. For example: [10:00:21] ABILIS_CPX:`d d ctislink` RES:CtiSLink ------------------------------------------------------------------ HDLC_Over_ISDN_B-Channel MaxConn:9 CurrConn:0 - Sessions ------------------------------------------------------------- SES: STATE: CG: [SCG:] CD: [SCD:] RES: ------------------------------------------------------------------------ - LISTEN X25-999 CPISDN - LISTEN Pv-1 ABILIS1-ABILIS2 - LISTEN Pv-3 ABILIS1-ABILIS3 2 CONN -TO 0211223344 Ip-10 ABILIS1-ABILIS5

With the d d ctislink command, it's possible to display the resources (with their SGI value) ready to receive a connection over the B-channel. For example:

[10:00:21] ABILIS_CPX:d d ctislink

RES:CtiSLink ------------------------------------------------------------------
       HDLC_Over_ISDN_B-Channel
       MaxConn:9           CurrConn:0
       - Sessions -------------------------------------------------------------
       SES:  STATE:        CG: [SCG:]           CD: [SCD:]           RES:
       ------------------------------------------------------------------------
       -     LISTEN                                                  X25-999
                           CPISDN
       -     LISTEN                                                  Pv-1
                           ABILIS1-ABILIS2
       -     LISTEN                                                  Pv-3
                           ABILIS1-ABILIS3
       2     CONN    -TO                        0211223344           Ip-10
                           ABILIS1-ABILIS5

76.1.3. How can I manage the backup over ISDN autoconnection?

The BAC parameter controls the backup over ISDN autoconnection mode. With value DOD the behaviour supports the Dial-On-Demand rules, while with value NAILED-UP the B-channel is spontaneously connected at boot, and reconnected in case of drop for any reason. In case of connection failure the retries are managed via BRTY, BNRTY, BTB parameters. Regardless of BAC value, i.e. even if BAC:NAILED-UP, if the state of the PLINK gets READY the SLINK (B channel) will be closed after a short timeout, in the same way as when BAC:DOD.

With the DDT and VDT parameters, it's possible to configure the Data and Voice Disconnect Time-out for every resource over B channel and every resource with backup. With the value NOMAX it's possible to disable the inactivity timers.

76.1.4. Is it possible to connect ISDN phones to BRI/BRI-HFC cards?

Yes, it is, but Abilis doesn't provide power supply; ISDN phones MUST BE self-supplied!

76.1.5. Why (and how to) enable/disable analog ports on a NT1 Plus device?

If Abilis is connected to a NT1 Plus device, it's recommended to disable the analog ports.

Consider the following scheme: when all VoIP channels are busy, a new incoming call is refused by the CTIP:33 and the NT device forwards the call to the analog ports; in this way the call doesn't reach the BUSY state but the ALERTING state.

Let's see how to disable and enable the analog ports.

How to DISABLE analog ports on a NT1 Plus device:
1. Verify that there aren't current calls.
2. Temporarily disconnect from the NT device the cable(s) coming from Abilis.
3. Connect an analog BCA telephone with DTMF to the analogic port a1/b1 (RJ11).
4. Disable the a1/b1 port dialling the sequence: # * # # * # * 1 9 * 0 #
5. Hook the telephone.
6. Disable the a2/b2 port dialling the sequence: # * # # * # * 2 9 * 0 #
7. Hook the telephone.
8. Disconnect the telephone from the NT device.
9. Connect to the NT device the cable(s) coming from Abilis.
How to ENABLE analog ports on a NT1 Plus device:
1. Verify that there aren't current calls.
2. Temporarily disconnect from the NT device the cable(s) coming from Abilis.
3. Connect an analog BCA telephone with DTMF to analogic connector a1/b1 (RJ11).
4. Enable the a1/b1 port dialling the sequence: # * # # * # * 1 9 * 100011 #
5. Hook the telephone.
6. Enable the a2/b2 port dialling the sequence: # * # # * # * 2 9 * 100011 #
7. Hook the telephone.
8. Disconnect the telephone from the NT device.
9. Connect to the NT device the cable(s) coming from Abilis.


Chapter 76. FAQ - Frequently Asked Questions		76.2. POTS ports