Networking ATA, Callmanager and Voice gateway with FXS (phones)

Posted: May 26, 2006 by sankar in Analog, ATA186, Gatekeeper, Gateways, IOS Gateways

Setup :

a. Callmanager 4.1 with IP phone extension 1005 (Callmanager IP

b. ATA 186 with H323 load , 2 phones with extension 2000, 2001 (ATA IP

c. H323 gateway with FXS ports with phone extension 3010, 3011 (Gateway IP

d. Gatekeeper with 3 zones created (one for CM, one for gateway and one for ATA) (GK IP

******Key things to note about GK registration*******

 a. ATA register with GK as Terminal

 b. H323 gateway registers with GK as Voip-GW

 c. Callmanager can be registered to the GK as Voip-GW or Terminal (Trunk configuration page)

 d. GK uses proxying between Terminals and Voip-GW's. So take special note to disable proxy from each zone that involes a Terminal and Voip-GW.

Configuration of ATA

a. Use E164 numbers in UID0 and UID1.

b. No need to set Login ID's if using E.164 numbers for GK registration

c. Specify the GKID field with the zone name (with out domain name)

d. Specify the GKOrProxy field with the IP address of the gatekeeper (

e. ATA cannot specify a tech prefix (as it registers as a terminal)

Configuration of GK


GateKeeper#sh gatek end
CallSignalAddr  Port  RASSignalAddr   Port  Zone Name         Type    F
————— —– ————— —– ———         —-    —    1721    1739  ATA               TERM
    ENDPOINT ID: 8232D55C00000001  VERSION: 2 age= 233 secs
    E164-ID: 2001    1720    1719  ATA               TERM
    ENDPOINT ID: 82609CF000000002  VERSION: 2 age= 233 secs
    E164-ID: 2000   55419   53824 CM41              VOIP-GW
    ENDPOINT ID: 824FC0F400000004  VERSION: 2 age= 18 secs
    H323-ID: CCM_1   1720   50439 gateway           VOIP-GW
    ENDPOINT ID: 8230A09400000004  VERSION: 2 age= 40 secs
    E164-ID: 3011
    E164-ID: 3010
Total number of active registrations = 4


Gateway Configuration

interface Ethernet0/0
 ip address
 h323-gateway voip interface
 h323-gateway voip id gateway ipaddr 1719
 h323-gateway voip h323-id Gateway
 h323-gateway voip tech-prefix 1#

dial-peer voice 1 pots
 destination-pattern 3010  —– phone 1
 port 1/0/0

dial-peer voice 2 pots
 destination-pattern 3011  —– phone 2
 port 1/0/1

dial-peer voice 10 voip
 destination-pattern 1…      —— Pattern for calls to Callmanager , No need to prepend tech prefix as 4# is  default tech prefix

 session target ras
 dtmf-relay h245-alphanumeric
 codec g711ulaw
dial-peer voice 10 voip
 destination-pattern 2…     ——- Pattern for Calls to ATA, No need for tech prefix as ATA registers to GK as terminal
 session target ras
 dtmf-relay h245-alphanumeric
 codec g711ulaw


Configuration of Callmanager

a. Add a gatekeeper (with GK's ip address,

b. Add a Trunk (Gatekeeper controlled) and specify tech prefix 4#, the gatekeeper that was previously added, Terminal type (VOIP-GW or Terminal)  and zone name (CM41)

c. Set the significant digits on incoming calls to All.

d. Add a route pattern [23]XXX and route the calls through the trunk created in step 2. 2XXX is for ATA phones and 3XXX is for FXS phones

  1. kabbeboy says:

    In gateway configuration you mention that it will prepend 4#. I thought it will prepend the tech prefix you configured on the ethernet interface.. ie 1# . So if we dial 1001 then it will go to gatekeeper with 1#1001. Correct me if I am wrong..
    Some how I can not see the screen shots in my browser u put in your site . What should I do ?
    Or else nice post. Keep up the good job..

  2. cciestudy says:

    The tech prefix you configure on the ethernet interface is used when the gateway registers with the gatekeeper.

    When a call is placed and you need to prepend the tech prefix, then you would need to use the “prefix-digits” commands under the “dial-peer” statements.

    Are you using IE browser? It normally works with IE. I have run into issues with Firefox.

  3. cciestudy says:

    You are right. Just read in the SRND that gateways will automatically prefix tech prefix for outgoing calls and will strip the tech prefix for incoming calls. But Callmanager does not do so. So you would need to use prefix digits and translation patterns to do so

    Please ignore my previous post.

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