PRI no inbound call

hello i am trying to connect two asterisk boxes with a pri link. using two sangoma a101d cards. i have developed the following setup

Sip/2106-------------->serverA++++++++++++++++serverB<-----------------------Sip/1610
wanrouter and pri are working well.
but i am getting error on inbound call.
when i called 1610 from 2106 is got following error on serverB CLI.

###########################CLI serverB####################################
< Protocol Discriminator: Q.931 (8) len=46
< Call Ref: len= 2 (reference 3/0x3) (Originator)
< Message type: SETUP (5)
< [04 03 80 90 a3]
< Bearer Capability (len= 5) [ Ext: 1 Q.931 Std: 0 Info transfer capability: Speech (0)
< Ext: 1 Trans mode/rate: 64kbps, circuit-mode (16)
< User information layer 1: A-Law (35)
< [18 03 a1 83 81]
< Channel ID (len= 5) [ Ext: 1 IntID: Implicit PRI Spare: 0 Preferred Dchan: 0
< ChanSel: Reserved
< Ext: 1 Coding: 0 Number Specified Channel Type: 3
< Ext: 1 Channel: 1 ]
< [28 0d 53 68 6f 69 65 62 20 41 72 73 68 61 64]
< Display (len=13) [ Shoieb Arshad ]
< [6c 06 21 80 32 31 30 36]
< Calling Number (len= 8) [ Ext: 0 TON: National Number (2) NPI: ISDN/Telephony Numbering Plan (E.164/E.163) (1)
< Presentation: Presentation permitted, user number not screened (0) ‘2106’ ]
< [70 05 a1 31 36 31 30]
< Called Number (len= 7) [ Ext: 1 TON: National Number (2) NPI: ISDN/Telephony Numbering Plan (E.164/E.163) (1) ‘1610’ ]
< [a1]
< Sending Complete (len= 1)
– Making new call for cr 3
– Processing Q.931 Call Setup
– Processing IE 4 (cs0, Bearer Capability)
– Processing IE 24 (cs0, Channel Identification)
– Processing IE 40 (cs0, Display)
– Processing IE 108 (cs0, Calling Party Number)
– Processing IE 112 (cs0, Called Party Number)
– Processing IE 161 (cs0, Sending Complete)
q931.c:3504 q931_receive: call 3 on channel 1 enters state 6 (Call Present)
– Extension ‘1610’ in context ‘testingzap’ from ‘2106’ does not exist. Rejecting call on channel 0/1, span 1
NEW_HANGUP DEBUG: Calling q931_hangup, ourstate Call Present, peerstate Call Initiated
q931.c:3099 q931_release_complete: call 3 on channel 1 enters state 0 (Null)

Protocol Discriminator: Q.931 (8) len=9
Call Ref: len= 2 (reference 3/0x3) (Terminator)
Message type: RELEASE COMPLETE (90)
[08 02 81 81]
Cause (len= 4) [ Ext: 1 Coding: CCITT (ITU) standard (0) Spare: 0 Location: Private network serving the local user (1)
Ext: 1 Cause: Unallocated (unassigned) number (1), class = Normal Event (0) ]
NEW_HANGUP DEBUG: Calling q931_hangup, ourstate Null, peerstate Null
NEW_HANGUP DEBUG: Destroying the call, ourstate Null, peerstate Null

###########################extensions.conf ###################################
[testingzap]
exten => _X.,1,Answer()
exten => _X.,2,Playback(hello-world)
exten => _X.,3,Dial(SIP/1610)
exten => _X.,3,Hangup()

testingzap is defined as context in zapata.conf

thanks in advance