Network connectivity testing
Cisco TelePresence ISDN Gateway 2.1 Online help (Printable format) 70 of 135
Network connectivity testing
The Network connectivity page can be used for troubleshooti ng issues that arise because of problems
in the network between the Cisco TelePresence ISDN Gatewa y and a remote video conferencing
device being called (or a device from which a user is attem pting to call the ISDN Gateway).
The Network connectivity page enables you to attempt to 'ping' another device from the ISDN
Gateway's web interface and perform a 'traceroute' of the net work path to that device. The results
show whether or not you have network connectivity between th e ISDN Gateway and another device.
You can see from which port the ISDN Gateway will route to th at address. For a hostname, the IP
address to which it has been resolved will be displayed.
To test connectivity with a remote device, go to Network > Connectivity. In the text box, en ter the IP
address or hostname of the device to which you want to tes t connectivity and click Test connectivity.
For each successful 'ping', the time taken for the ICMP echo p acket to reach the host and for the reply
packet to return to the ISDN Gateway is displayed in m illiseconds (the round trip time). The TTL (Time
To Live) value on the echo reply is also displayed.
For each intermediate host (typically routers) on the route b etween the ISDN Gateway and the remote
device, the host's IP address and the time taken to receive a response from that host is shown. Not all
devices will respond to the messages sent by the ISDN G ateway to analyse the route; routing entries
for non-responding devices is shown as <unknown>. Som e devices are known to send invalid ICMP
response packets (e.g. with invalid ICMP checksums); these r esponses are not recognized by the
ISDN Gateway and therefore these hosts' entries are also s hown as <unknown>.
Notes:
The ping message is sent from the ISDN Gateway to the IP ad dress of the endpoint that you enter.
Therefore, if the ISDN Gateway has an IP route to the given IP address, regardless of whether that
route lies out of port A or port B, the ping will be successful. This feature allo ws the ISDN Gateway’s
IP routing configuration to be tested, and it has no securit y implications.
If you are unable to ping the device then check your network configuration especially any firewalls
using NAT.