Cisco C827-4V router issues

Question

Hi,
I have the following escenario and I'm having some issues getting calls to most of the offices; the strange part it that the calls work for about 4 out of the 18 locations and they're all configured the same; here is the equipment I'm using:
Cisco 827--------PIX-------Cable modem
The 827 has a 4 port voice module and this is what happens when we try to call other locations which in most cases have 2620 or 2621 routers with voice cards as well:
1 San Antonio 001, rings once, dialtone, additional digits do not break dialtone, times out with dead air
2 Portland 002, rings once, dialtone, additional digits do not break dialtone, times out with dead air
5 San Diego 005, rings once, dialtone, additional digits do not break dialtone, times out with dead air
6 Phoenix 006, rings once, dialtone, additional digits do not break dialtone, times out with dead air
7 San Jose 007, rings once, dialtone, additional digits do not break dialtone, times out with dead air
8 Denver 008, rings once, dialtone, additional digits do not break dialtone, times out with dead air
9 Dallas 009, rings once, dialtone, additional digits do not break dialtone, times out with dead air
10 Chicago 010, rings once, dialtone, additional digits do not break dialtone, times out with dead air
11 Boston 011, rings once, dialtone, additional digits do not break dialtone, times out with dead air
12 Houston 012, rings once, dialtone, additional digits do not break dialtone, times out with dead air
13 Garden Grove 013, rings once, dialtone, additional digits do not break dialtone, times out with dead air
14 Seattle 014, rings once, dialtone, additional digits do not break dialtone, times out with dead air
26 Minneapolis 026, rings once, dialtone, additional digits do not break dialtone, times out with dead air
3 Glendale 003, Dead air, times out with a busy
18 Hartford 018, Works
19 Charlotte 019, Works
21 Cleveland 021, Works
22 South Beloit 022, Works
This setup worked long time ago when the router was on the outside with no firewall; and again with the current set up, it works for 4 of the locations and I'd like to know if somebody over there has a similar scenario and would like to share any information.
Thanks very much

Answer 1

I think its some config problems in the PIX .
Add commands the following commands in PIX.
fixup protocol h323 h225 1720
fixup protocol h323 ras 1718-1719
http://www.cisco.com/en/US/products/hw/vpndevc/ps2030/products_configuration_example09186a00801fc74a.shtml