I need help please:Problem with iax2

I need to join two asterisk.
In an office I have extensions that begin with 1. In another venue I have extensions beginning with 3.

On Server A believe a IAX2 trunk:
Trunk Name: Server2
context = from-internal
host = 192.168.0.31
qualify = yes
secret = mamabelen
type = peer
username = admin

User Context: admin
context = from-internal
host = 192.168.0.31
secret = mamabelen
type = user

On Server B believe a IAX2 trunk:
Trunk Name: Server1
context = from-internal
host = 192.168.25.246
qualify = yes
secret = mamabelen
type = peer
username = admin

User Context: admin
context = from-internal
host = 192.168.25.246
secret = mamabelen
type = user

I write this command on both servers:
IAX2 show peers

Server A Sample:
Asterisk * CLI> IAX2 show peers
Name / Username Host Mask Port Status
Server2/admin 192.168.0.31 (S) 255.255.255.255 4569 OK (109 ms)

Server B Sample:
Name / Username Host Mask Port Status
Server1/admin 192.168.25.246 (S) 255.255.255.255 4569 OK (126 ms)

But when I try to make a call from A to B for that I created Trunk got this error:

  • Executing [s @ macro-dialout-trunk: 19] Dial ( “SIP/3000-b6503dd0”, “IAX2/Server2/1005 | 300 |”) in new stack
    • Called Server2/1005
    • Hungup ‘IAX2/Server2-15366’
      == Everyone is busy / congested at this time (1:0 / 0 / 1)
    • Executing [s @ macro-dialout-trunk: 20] Goto ( “SIP/3000-b6503dd0”, “s-CHANUNAVAIL | 1”) in new stack
    • Goto (macro-dialout-trunk, s-CHANUNAVAIL, 1)
    • Executing [s-CHANUNAVAIL @ macro-dialout-trunk: 1] GotoIf ( “SIP/3000-b6503dd0”, “1? Noreport”) in new stack
    • Goto (macro-dialout-trunk, s-CHANUNAVAIL, 3)
    • Executing [s-CHANUNAVAIL @ macro-dialout-trunk: 3] NoOp ( “SIP/3000-b6503dd0”, “TRUNK Dial failed due to CHANUNAVAIL (HANGUPCAUSE: 0) - failing through to other trunks”) in new stack
    • Executing [1005 @ from-internal: 5] Macro ( “SIP/3000-b6503dd0”, “outisbusy |”) in new stack
    • Executing [s @ macro-outisbusy: 1] Playback ( “SIP/3000-b6503dd0”, “all-circuits-busy-now | noanswer”) in new stack

I also having this problem, when I type iax2 show peers, the trunk i configured is ready to use. Yet when I make calls, it says its congested. Can anyone give some advise on this problem thanks.