List at least four benefits of using H.323 as a gateway protocol.
When you are configuring an H.323 gateway on a CallManager, what information do you enter for Device Name?
Enter the IP address of the gateway. If CallManager can reach the gateway with more than one IP address, use the h323-gateway voip bind srcaddr ip-address command to select which address to use.
Name four types of DTMF Relay that H.323 uses.
H.245 uses Cisco-RTP, RTP-NTE, H.245 Alphanumeric, and H.245 Signal.
What commands must you enter for a Cisco gateway to use H.323 Fast Start?
Cisco gateways assume that H.323 Fast Start is used. No commands are necessary to configure it.
Briefly describe toll bypass.
With toll bypass, calls between company locations are sent over the IP network as VoIP when bandwidth is available, and they are routed over the PSTN when no bandwidth is available.
If you configure conflicting commands globally under the voice service voip configuration mode, and under the dial peer using voice class, which commands will the router use?
The router will use the most explicating applied commands, which in this case are the commands under the dial peer. It will use global commands only if more explicit ones are not configured.
How do you prevent active calls from being terminated when the CallManager becomes unreachable?
Turn off H.225 keepalives between the gateway and CallManager. The commands to do this are as follows:
GW1(config)#voice service voip
GW1(conf-serv-h323)#no h225 timeout keepalive
Part I: Voice Gateways and Gatekeepers
Gateways and Gatekeepers
Part II: Gateways
Media Gateway Control Protocol
Session Initiation Protocol
Connecting to the PSTN
Connecting to PBXs
Connecting to an IP WAN
Influencing Path Selection
Configuring Class of Restrictions
SRST and MGCP Gateway Fallback
Using Tcl Scripts and VoiceXML
Part III: Gatekeepers
Part IV: IP-to-IP Gateways
Cisco Multiservice IP-to-IP Gateway
Appendix A. Answers to Chapter-Ending Review Questions