Gatekeeper alias command

[emrekoyuncu]

I am trying to understand the usage of the alias command. I have two CMs and H323 ATA registered to the gatekeeper. I don't want to use tech-prefixes and I want gatekeeper to make all of its routing decisions based on the registered E164IDs. As CM does not register the E164 #s , I configured the following alias entry but it does not seem to work. Can somebody enlighten me about the usage of this command ? Thanks

gatekeeper

zone local home cisco.com

zone local office cisco.com

alias static 172.25.3.102 1720 gkid office gateway voip ras 172.25.3.102 1719 e164 3903

no use-proxy office default inbound-to terminal

no use-proxy office default outbound-from terminal

no shutdown

Router#sh gatekeeper endpoints

GATEKEEPER ENDPOINT REGISTRATION

================================

CallSignalAddr Port RASSignalAddr Port Zone Name Type Flags

--------------- ----- --------------- ----- --------- ---- -----

172.25.5.11 2037 172.25.5.11 2665 office VOIP-GW

H323-ID: LabCMTrunk_1

Voice Capacity Max.= Avail.= Current.= 2

172.25.3.102 49232 172.25.3.102 49229 office VOIP-GW

H323-ID: EmreHomeTrunk_1

Voice Capacity Max.= Avail.= Current.= 0

172.25.3.102 1720 172.25.3.102 1719 office VOIP-GW S

E164-ID: 3903 (static)

192.168.80.55 1720 192.168.80.55 1719 office TERM

H323-ID: port0=333

E164-ID: 1200

192.168.80.55 1721 192.168.80.55 1739 office TERM

H323-ID: port1=333

E164-ID: 1300

[michael_davis]

I suspect the problem is not with the alias statement but rather with anonymous device support in CCM.

Alias statements provide the simplest form of RAS. They tell the GK to return a specific IP when a particular e164 is ARQed. No tech prefix is required, and default tech prefixes are not used in matching the e164. However, aliases _do_not_ depend on a endpoint be registered. Indeed, aliases are ideal for situations where an endpoint doesn't support ras. So there is no call state maintained in the GK.

I believe you are seeing the failure of Anonymous Device support in CCM. CCM will not accept h225 call setups from devices it is not aware of. There are three ways to get the CCM to accept a call from an h323 endpoint:

1) Configure the device in CCM as a h323 gateway. When a new CS from a h323 endpoint arrives, CCM compares the source IP address against those configured as gateways. If the IP is unknown, it will

2) ARQ its GK controlled trunks. If a GK responds with an ACF, then CCM will accept the call. If it receives an ARJ, or there are no GK controlled trunks, CCM will reject the Call. Also, since aliases don't require the GK to maintain call state information,

3) You may override this behavior in CallManager Service parameters by setting "Accept Unknown TCP Connection" to true. This is not a good idea as it could open you up to toll fraud.

HTH,

Michael

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