MX-ONE with Branch Offices in Different PSTN Areas

Description

The scenario in Figure 1 consists of a main office served by the MX-ONE Telephony System and a number of branch offices served by several IP telephones logging from the main office MX-ONE. The main office and the branch offices are located in PSTN areas with different area codes (91, 93, 95, and 96). Each branch office is represented by a different domain, so every IP telephone in an office is associated to the branch office domain.

The accesses to PSTN are set up at the main office MX-ONE (route 61) and at the branch offices' SBNs.

All extensions, both in main and branch offices, use the same code to access the PSTN (that is, 00). However, the MX-ONE configuration provides local presence to the extensions placed in branch offices. If a number is dialed without any area code, the call will be routed to the PSTN through the calling party branch office SBN and the calling party number will be prefixed with its own area code.

This is accomplished by adding the area code to the dialed external number so the proper SBN can be addressed. The addition of area code to the dialed external number is provided by LCR tables. For IP extensions in the branch offices, the area code is set per domain. For other extensions in main office, the area code is set per media gateway or LIM. Notice that PSTN access code 00 must be defined as LCR access code (LAC) to be able to use the LCR tables.

The local presence and local hop-off functions are achieved by means of IP networking tie-lines between the MX-ONE and each of the SBNs and proper configuration of external destinations and prefixes. Separate routes allow to prefix the calling party number according to the PSTN area where the called party is located (that is, 91, 93, 95, and 96).

It is required to enable the 112 emergency calls in all offices, where the following emergency number formats must be valid:
  • Emergency number (that is, 112)
  • Route access code to the PSTN + emergency number (that is, 00112)
The emergency calls must be enabled for logged-on and logged-off IP telephones, and it is also required that the emergency center can dial back to the calling user. In this case the emergency center uses the received calling number in the emergency call to dial back to the calling user.
Figure 1. Example of an extended configuration with Remote Branch Offices

Prerequisites

  • The IP extensions must be initiated. See the operational directions for IP Handling.
  • The domains for the IP telephones must be initiated for all the branch offices. See the operational directions for IP Handling.
  • The area codes per LIM and per domain must be initiated. See the operational directions for LEAST COST ROUTING and the operational directions for IP Handling.
  • The public route 61 is already initiated. See the operational directions for IP NETWORKING.
  • The IP networking interfaces and tie-lines 63, 65, and 66 to the branch offices must be completely initiated. See the operational directions for IP NETWORKING and see the operational directions for ROUTE DATA.
  • The prefixes for public calls must be also initiated. See the operational directions for IP NETWORKING.
  • LCR tables are already set up to route the public calls to the SBN closest to the called party PSTN area. Therefore, the LAC=00 is already initiated and area codes added, so the translations lead to public destinations associated to the IP networking tie-lines to the SBNs that finally route the calls to the PSTN. See the operational directions for LEAST COST ROUTING.
  • The rules and regulations of every local emergency center must be known with regard to the A-number handling.
  • The non-emergency parameters of the IP telephones configuration file must be already initiated. The domain name initiated must be "madrid.es". See the operational directions for IP HANDLING.
  • The SBN must be completely set up to enable the survivability, local presence, and local hop-off functions. See the operational directions for ENTERPRISE BRANCH NODE, SBN.
  • Prefixing of A-number must be initiated.

Execution

The following steps must be carried out:
Emergency Number:

  • Step 1. Change the existing public destination configuration

    As LCR tables are already initiated, no changes are needed in the current destination configuration.Example: In the scenario represented above (see Figure 1), the call will be routed through IP networking route 63 when someone dials 00931234567 from an IP telephone in any office. The IP networking route 63 is associated to the external destination 93.

  • Step 2. Initiate the LAC

    number_initiate -numbertype lc -number 112

  • Step 3. Modify the LCR tables

    As the emergency number dialed is the same in every office (112 or 00112), LCR entries must be set to add the area code associated to the domain of the calling IP extension, so the call will be routed towards the local emergency center in that area.

    In the scenario represented above (see Figure 1), NLT (Number Length Table) should already be set up as follows:LCDDI:TAB=NLT,ENTRY=00,ACF=Y;

    Example: In this scenario, the call will be routed through IP networking route 63 when someone dials 001234567 from an IP telephone in "barcelona.es" (AC=93). The IP networking route is associated to the external destination 93.

    Note: It is possible to dial external numbers with or without PSTN area code. This can be achieved by the following entries in External Number Table(ENT).

    LCDDI:TAB=ENT,ENTRY=0091,TRC=2;

    LCDDI:TAB=ENT,ENTRY=0093,TRC=2;

    LCDDI:TAB=ENT,ENTRY=0095,TRC=2;

    LCDDI:TAB=ENT,ENTRY=0096,TRC=2;

    For the emergency number, it is needed to add the leading 00 when 112 is dialed.

    LCDDI:TAB=ENT,ENTRY=112,PRE=00;

    Once the area code is added, it is needed to manipulate the number in order to address the proper emergency destination. In other words, the area code added above allows to address existing destinations (that is, 91, 93, 95, and 96), which are not qualified as emergency destinations.

    In this example, for each 9x destination there will be a 2x emergency destination.

    LCDDI:TAB=FDT,FRCT=1,PRE=2,TZONE=1&&3;

    LCDDI:TAB=DNT1,ENTRY=0091112,TRC=3,FRCT=1;

    LCDDI:TAB=DNT1,ENTRY=0093112,TRC=3,FRCT=1;

    LCDDI:TAB=DNT1,ENTRY=0095112,TRC=3,FRCT=1;

    LCDDI:TAB=DNT1,ENTRY=0096112,TRC=3,FRCT=1;

    Other public numbers will be processed according to the following entries:

    LCDDI:TAB=FDT,FRCT=2,PRE=9,TZONE=1&&3;

    LCDDI:TAB=DNT2,ENTRY=00,TRC=3,FRCT=2;

Emergency Destinations: In order to route the emergency calls to the local emergency centers through the branch offices SBNs, emergency destinations have to be associated to IP networking routes between the main office and the SBNs.

  • Step 1. Initiate the external destination in the number series

    number_initiate -numbertype ed -number 21,23,25,26

  • Step 2. Initiate the emergency external destination

    Initiation of the emergency destination associated to the public route 63 to the PSTN network for the emergency center at main office.

    RODDP:DEST=91; (Make note of destination data).

    RODDI:DEST=21,ROU=61,SRT=3,ADC=0305000000000050005000010100;

    Notice that the SRT, TRC, and PRE parameters may need specific values in order to compound the called party number in the form required by the PSTN.

    Initiation of the emergency destination associated to the tie-lines to the SBNs for the emergency centers at branch offices.

    RODDP:DEST=93; (Make note of destination data).

    RODDI:DEST=23,ROU=63,SRT=3,ADC=0305000000000050005000010100;

    RODDP:DEST=95; (Make note of destination data).

    RODDI:DEST=25,ROU=65,SRT=3,ADC=0305000000000050005000010100;

    RODDP:DEST=96; (Make note of destination data).

    RODDI:DEST=26,ROU=66,SRT=3,ADC=0305000000000050005000010100;

Emergency IP Networking Route: Initiate the IP networking route by using the following commands:
  1. ROCAI:ROU=70,SEL=0110100000000010,SIG=011110101190,TRAF=03151515,TRM=4,SERV=0010000007,BCAP=001100;
  2. RODAI:ROU=70,TYPE=TL65,VARC=00000001,VARI=00000101,VARO=00000000;
  3. RIANI:ROU=70,LROUID="ROUID70";
  4. ROEQI:ROU=70,TRU=1-1&&1-16;
Domain Emergency Data:
  • MAIN OFFICE, "madrid.es"

    • Step 1. Initiate the dial-back position

      number_initiate -numbertype ex -number 2345

      extension -i -d 2345 --csp 1 --lim 1 --emergency yes

    • Step 2. Initiate the domain

      ip_domain -p (Make note of the domain data)

      ip_domain -e --domain-name madrid.es

      ip_domain -i --domain-name madrid.es --ip-net 130.100.21.0/24 --emedir 2345 --area-code 91

      Optionally also include the --location-id parameter, if outgoing SIP route with the PANI Header option is supported/used. This is also valid for the Branch office nodes below.

  • BRANCH OFFICE 1, "sevilla.es"

    • Step 1. Initiate the dial-back position

      number_initiate -numbertype ex -number 2346

      extension_profile -i --csp 1 --ext-cdiv 11500000100000 --ext-npres 0010000 --ext-roc 000001 --ext-serv 101151112000000000000000001100 --ext-traf 1100151515

      extension -i -d 2346 --csp 1 --lim 1 --emergency yes

    • Step 2. Initiate the domain

      ip_domain -p (Make note of the domain data)

      ip_domain -e --domain-name sevilla.es

      ip_domain -i --domain-name sevilla.es --ip-net 130.72.210.0/24 --emedir 2346 --area-code 95

  • BRANCH OFFICE 2, "barcelona.es"

    • Step 1. Initiate the dial-back position

      number_initiate -numbertype ex -number 2347

      extension_profile -i --csp 1 --ext-cdiv 11500000100000 --ext-npres 0010000 --ext-roc 000001 --ext-serv 101151112000000000000000001100 --ext-traf 1100151515

      extension -i -d 2347 --csp 1 --lim 1 --emergency yes

    • Step 2. Initiate the domain

      ip_domain -p (Make note of the domain data)

      ip_domain -e --domain-name barcelona.es

      ip_domain -i --domain-name barcelona.es --ip-net 130.64.100.0/24 --emedir 2347 --area-code 93

  • BRANCH OFFICE 3, "valencia.es"

    • Step 1. Initiate the dial-back position

      number_initiate -numbertype ex -number 2348

      extension_profile -i --csp 1 --ext-cdiv 11500000100000 --ext-npres 0010000 --ext-roc 000001 --ext-serv 101151112000000000000000001100 --ext-traf 1100151515

      extension -i -d 2348 --csp 1 --lim 1 --emergency yes

    • Step 2. Initiate the domain

      ip_domain -p (Make note of the domain data)

      ip_domain -e --domain-name valencia.es

      ip_domain -i --domain-name valencia.es --ip-net 130.82.90.0/24 --emedir 2348 --area-code 96

Initiation of Dial-Back Destinations:

  • Step 1. Initiate the external destination in the number series

    number_initiate -numbertype ed -number 4532

  • Step 2. Associate the external destinations with the emergency route

    RODDI:DEST=4532,ROU=70,SRT=1,ADC=0305000000000050005000000000;

DBC 4xx Configuration (H.323 Only):
  • Configuration in the main office MX-ONE
    • [Emergency]
      • System1=MX-ONE
      • Address1=10.1.18.91
      • Port1=1720
      • EmergencyNr=112
      • RouteID=ROUID70
      • A-Number=913394532
    • [WAP]
      • RouteAccessNumber=00
  • Configuration in the branch office 1
    • [Emergency]
      • System1=MD-E
      • Address1=10.1.26.10
      • Port1=1720
      • EmergencyNr=112
      • A-Number=953394532
  • Configuration in the branch office 2
    • [Emergency]
      • System1=MD-E
      • Address1=10.1.40.10
      • Port1=1720
      • EmergencyNr=112
      • A-Number=933394532
  • Configuration in the branch office 3
    • [Emergency]
      • System1=MD-E
      • Address1=10.1.60.10
      • Port1=1720
      • EmergencyNr=112
      • A-Number=963394532
Initiate the SBN in the Branch Office with the Net Manager:

  • Step 1. Initiate the dial back position

    A local extension, operator group, hunt group, or ring group must be initiated in the SBN to enable the emergency center to dial back to branch office logged off extensions. See the operational directions for SURVIVABLE BRANCH NODE, SBN.

  • Step 2. Initiate the emergency destination

    A destination code (that is, 112) must be initiated to route the emergency calls to the PSTN, when the user dials the emergency number directly without the PSTN access code. See the operational directions for SURVIVABLE BRANCH NODE, SBN.

Verification

These considerations should be taken into account:
  • Avoid using the live emergency number when testing.
  • When making a final test call to the emergency number, be careful to check the local regulations.
After the execution phase the following configuration is obtained, see the following figure.
Figure 2. Configuration after initiation of data to support Emergency Calls

To verify the new configuration for emergency calls, the following actions can be done.

Emergency Calls from Logged-On IP Telephones Located in the Main Office:
  • Dial the 112 emergency number from a logged-on IP telephone and check that the emergency center is called.
  • Dial the 00112 emergency number from a logged-on IP telephone and check that the local emergency center is called.
  • Dial the received calling party number in the emergency center and check that the calling user is dialed back.
Emergency Calls from Logged-Off IP Telephones Located in the Main Office:
  • Dial the 112 emergency number from a logged-off IP telephone and check that the emergency center is called.
  • Dial the 00112 emergency number from a logged-off IP telephone and check that the local emergency center is called.
  • Dial the received calling party number in the emergency center and check that the calling user is dialed back.
Emergency Calls from Logged-On IP Telephones Located in a Branch Office:
  • Dial the 112 emergency number from a logged-on IP telephone and check that the emergency center is called.
  • Dial the 00112 emergency number from a logged-on IP telephone and check that the local emergency center is called.
  • Dial the received calling party number in the emergency center and check that the calling user is dialed back.
  • Repeat the steps in every branch office.
Emergency Calls from Logged-Off IP Telephones Located in a Branch Office:
  • Dial the 112 emergency number from a logged-off IP telephone and check that the emergency center is called.
  • Dial the 00112 emergency number from a logged-off IP telephone and check that the local emergency center is called.
  • Dial the received calling party number in the emergency center and check that the calling user is dialed back.
  • Repeat the steps in every branch office.
Parent topic: Example Scenarios
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