Voip; Advanced Features - ZyXEL Communications ZYWALL P1 User Manual

Chapter 25 Troubleshooting

25.4 VoIP

I cannot make VoIP calls.
Click ADVANCED > ALG and enable either SIP or H.323 (whichever one you are using).
See Chapter 20 on page 323
I cannot receive VoIP calls.
See the troubleshooting suggestions for
You may also need to adjust the SIP timeout. Most SIP clients have an "expire" mechanism
indicating the lifetime of signaling sessions. The SIP user agent sends registration packets to
the SIP server periodically and keeps the session alive in the ZyWALL. If the SIP client does
not have this mechanism and makes no calls during the ZyWALL SIP timeout (default 60
minutes), the ZyWALL SIP ALG drops any incoming calls after the timeout period. Enter the
SIP signaling session timeout value.
My VoIP calls are not clear.
There might be a lot of traffic on the network. Look at the LEDs, and check
page 403. If the ZyWALL is sending or receiving a lot of information, try closing some
programs that use the Internet, especially peer-to-peer applications.

25.5 Advanced Features

I cannot set up a VPN tunnel to another device.
If the IPSec tunnel does not build properly, the problem is likely a configuration error at one of
the IPSec routers. Log into the web configurators of both IPSec routers (with the screens next
to each other if possible). Check the VPN settings methodically and slowly.
The system log can also help identify a configuration problem. Click LOGS to see the system
log. See Section 22.3.1 on page 347
click LOGS > Log Settings and make sure IKE and IPSec logging is enabled at both ends.
Then clear the log and re-attempt to build the tunnel.
• The network policy must use Tunnel if there is a NAT router between the IPSec routers.
408
for details on using SIP or H.323 through the ZyWALL.
"I cannot make VoIP calls." on page
for information on the log messages. You may need to
408.
Section 25.1 on
ZyWALL P1 User's Guide