Impulse is a network service provider serving primarily the United States. From time to time we have clients with a global presence who need to offer integrated voice services to remote offices. This document describes configuration of the Adtran Total Access 900 series to allow foreign telephone numbers to be directed to a Broadsoft or other SIP softswitch in these cases.
Configuration not discussed here should be done in the normal manner for SIP and fxs phones, PRI PBX, and the like.
Requirements and limitations
- Any Adtran E-model TA900 can accommodate one call on one local line.
- An Adtran TA924E-L2 can handle up to nine simultaneous calls on local lines.
- This configuration is tested and known to work with AOS 2.06. It should be compatible with later releases but this has not been verified.
- The customer must order local POTS lines in hunt from the telephone company and connect them to the Adtran IAD.
- For larger deployments, a PRI or CAS T1 from the local telephone company or a channel bank with sufficient FXO ports can be used by connecting it to one of the PBX PRI/T1 ports on the IAD. Note that the TA-900 is not compatible with E-1 circuits.
- If all trunk ports are in use, additional callers to the local number will hear a busy signal.
- Caller-ID from inbound calls to the trunk will display the name and number of the configured trunk group rather than the caller’s originating number.
- Adtran TA900 series IADs have a 120 VAC power supply as well as a 48-volt DC input intended for battery backup. When deploying outside of North America, the appropriate transformer or 48-volt DC supply will be required. Connecting the TA900 directly to 240-volt power will damage the IAD.
Step 1: Set up an analog voice trunk for the local lines.
voice trunk T01 type analog supervision loop-start
caller-id-override number-inbound 9999
connect fxo 0/1
connect fxo 0/2
connect fxo 0/3
rtp delay-mode adaptive
caller-id-override number-inbound above (example 9999) is the number of a valid Broadsoft extension that will be used for this trunk. This number should be programmed in Broadsoft with call-waiting to allow multiple calls. It can be a basic extension and it doesn’t need a valid dialable DID. Assign the seat a name in Broadsoft that will describe the call path, such as “Europe Office”.
trunk-number 5555 is the number of the auto-attendant, hunt group, or other end point that callers dialing the local number should reach. It can be any valid number, hunt group, ACD queue, or extension on the switch.
connect fxo 0/1 etc. specifies the active local lines connected to the Adtran. For other than the 924E-L2 model there is only a single RJ-11 FXO port, designated fxo 0/0. On the 924E-L2 there are eight ports on the Amphenol connector in positions 17 through 24 designated fxo 0/1 through fxo 0/8. A ninth line can be connected to RJ-11 fxo 0/0 as well.
The above configuration accepts incoming calls on the FXO ports, directs them to the digit string programmed under “trunk number” and shows the source as the number programmed as “caller-id override”.
Step 2: Set up SIP trunk to the Broadsoft with registration.
voice trunk T02 type sip
description “Softswitch Trunk”
sip-server primary 10.10.10.10
registrar primary 10.10.10.10
authentication username “9999”
register 9999 auth-name “9999” password “itsasecret”
The authentication username should match the caller-ID override programmed for the trunk above.
max-number-calls should match the number of FXO ports equipped.
Step 3: Add the local emergency number to the SIP proxy accept template.
ip sip proxy emergency-call-routing accept 911
911 is the emergency number for North America. For Europe and other parts of the world it may be 112, 999, or some other string. Verify locally before configuring.
Note that local prefixes can be added as emergency numbers as well which will force local calls out the FXO ports. For example, NXX-XXXX could be added as an emergency dialing template to cause local calls to use the FXO trunk. This hasn’t been extensively tested and may not scale.
Step 4: Configure a trunk group to route calls to the softswitch.
voice grouped-trunk SIP-TG
accept 5555 cost 0
This trunk group should also have accept statements for all other calls to be routed to the softswitch as you would normally configure a voice trunk group.
Step 5: Connect the voice lines to the Adtran IAD.
This can be done either directly or via a punch block or breakout box. Observe polarity. Some manipulation of the FXO gain and impedance settings from their defaults may be needed for appropriate level and balance.
Ensure that the IAD is properly grounded. Ideally this should be to the same point that the local telephone company uses for their demarcation point lightning protection ground.
Optional – Configure local call routing.
If local or in-country calls are to be routed out the local ports, a more scalable way than using the emergency template is to configure appropriate allowed digit strings and cost values in the grouped-trunk configuration for the analog trunk for local calls. In this mode the voice trunk group programming is used to choose call routes between the SIP trunk to the softswitch and the local FXO trunk. Some digit manipulation may be required depending on the dial plan in the area where this is deployed.
Test and troubleshooting:
Dial in to the local number assigned to the hunt group connected to the FXO ports. The programmed auto-attendant or hunt group should ring. The following standard voice debugging and show commands can be used for troubleshooting:
- show sip trunk-registration
- show sip proxy user
- debug voice switchboard
- debug voice trunkmanager
- debug voice verbose