As part of sipXecs release 4.2 support for Centralized Voicemail (CVM) is available.

Hardware Requirements

This functionality requires the following hardware:


It is recommended to use a PRI-E1 carrier between the Mediant1000 and the Legacy PBX since that provides 30 B-channels. If a PRI-T1 were used it would provide 23 B-channels. The PRI interface should be configured with the ISO flavor of QSIG and the QSIG supplementary services should be configured to use ASN.1 Integer coding, although ASN.1 Object coding could used if the appropriate configuration changes are made.

The CS1K Legacy PBX uses either a Coordinated Dialing Plan (CDP) or a Uniform Dialing Plan (UDP) for private networking. A CDP number is composed from the phone extension, and a UDP number is composed from the Access Code plus the Location Code (LOC) plus the phone extension. The following configuration examples use a CS1K UDP Dialing Plan with:


Legacy PBX Configuration

This section discusses the use of a Nortel CS1000, however other vendor's switches can also be used. Using Meridian1 (release 25.40 or later) or CS1K (release 4.0 or later), install software packages:

Using a PRI-E1 card (NTBK50AA Rlse07) with DIP switches:


D-channel configuration:

IFC: ISGF                                      (ISO QSIG)
RCAP: COLP NDI CCBI CCNI PRI DV3I CTI QMWI     (the "I" is for ASN.1 Integer coding)

Analog phone configuration:

HUNT 63921001     (CFB to voicemail)
CLS (Class of service):
  FNA  (forward no answer allowed)
  FBA  (forward busy allowed)
  XFA  (transfer allowed)
  WTA  (warning tone allowed)
  MWA  (message waiting allowed)
  LPA  (message waiting lamp allowed)
  CFXA (call forward external allowed)
  HTA  (Hunting allowed)
FTR CFW 16        (maximum number of digits in CFAC)
FTR FDN 63921001  (CFNA to voicemail after 4 rings)

Mediant1000 Configuration

To avoid an authentication problem when calls are forwarded back to the SCS:

The following parameters can be configured from the sipXecs configuration page:

Dial Plan Configuration

Configure the Dialing Plan on sipXecs:

Configure the external user on the sipXecs system (to match phone 8811 on the CS1K with LOC=394):

Note that these per-user settings can be automatically applied to a new user by first configuring a User Group for the new user. The prefix 81 will then be automatically added to the user 63948811 and used to auto-populate the External MWI and Call Forwarding fields. The required User Group settings are:

Call Scenarios

Legacy PBX setup

PBX home LOC=394

sipXecs setup:

Notes on ISDN numbering plan:

[UDP] indicates an ISDN NPI/TON=Private/Level1Regional
[unk] indicates an ISDN NPI/TON=Unknown/Unknown

SipXecs phone calls LegacyPBX phone

  1. 3201 dials 63948809
  2. Call gets forked to 8163948809 and gets presented to the Mediant1000 with a To Header 63948809
  3. Mediant1000 sends a SETUP to the Legacy PBX with CalledNumber=63948809[xecsdev:unk]
  4. Phone 8809 rings on legacy PBX
  5. Call to user 8809 times out and goes to sipXecs voicemail, which initiates a message deposit to user 63948809 mailbox.

LegacyPBX phone calls sipXecs phone

  1. Phone 8809 on legacy PBX dials 63923201
  2. LegacyPBX sends a SETUP to the Mediant1000 with CalledNumber=3923201[xecsdev:UDP]
  3. Phone 3201 rings
  4. Call to user 3201 times out and goes to sipXecs voicemail, which initiates a message deposit to user 3201 mailbox.

LegacyPBX phone calls LegacyPBX phone

  1. Phone 8809 dials 8811 and phone 8811 rings.
  2. Call gets Call Forwarded to 63921001.
  3. Redirected PRI-QSIG call is presented to the Mediant1000 with CalledNumber=3921001[xecsdev:UDP] and RedirectingNumber=3928811[xecsdev:UDP]
  4. Call goes through the Mediant1000 and gets presented to sipXecs with a Diversion Header of 3948811 and a To Header of 3921001.
  5. sipXecs voicemail answers the call to 3921001 and initiates a message deposit to user 63948811 mailbox.