Finally, in addition to pricing, backbone, and interconnection issues, customers should consider demarcation point (DP) issues when selecting an ISP and executing an agreement. A demarcation point is the point that differentiates the provider's network and responsibilities from the customer's network and responsibilities. This is particularly true in a service provider's dedicated hosting environment. It is important to understand the difference between the responsibilities o..
Comparison of PIM-DM and PIM-SM
One of the most confusing parts of the PIM-DM and PIM-SM designs is that it appears that if sources keep sending, and receivers keep listening, there is no difference between the end results of the end-user multicast packet flow using these two options. Once PIM-SM completes its more complicated processes, the routers near the receivers have all joined the SPT to the source, and the most efficient forwarding paths are used for each (S,G) tree. Although its underlying operatio..
Revision Control of IOS Configuration Files
All IOS configuration changes should be recorded and, if possible, a reason for each change should be logged. Such revision control may be achieved with a commercial package, such as CiscoWorks; or with public domain software, such as RCS. In the latter case, good results can be achieved simply by following these guidelines: Always write modified router configurations to a tftp server, using a well-known name for each router configuration file. Hav..
Call-Signaling TCP/UDP Ports in Use
In this design chapter, to keep the examples relatively simple, only Skinny Call Control Protocol (SCCP) ports (TCP ports 20002002) are used to identify call-signaling protocols. However, SCCP is by no means the only call-signaling protocol used in IP Telephony environments. Table 12-1 shows many of the TCP/UDP ports used in a Cisco CallManager environment. Table 12-1. Example TDP/UDP Ports Used in a Cisco CallManager Environment Prot..
Monitoring and Troubleshooting the Cisco IOS MLP LFI over Frame Relay Feature
This section introduces and explains the various Cisco IOS commands for monitoring and troubleshooting the Cisco IOS MLP LFI feature, configured over Frame Relay. The first Cisco IOS show command useful for monitoring LFI using MLP over Frame Relay virtual circuits is the show frame-relay pvc privileged EXEC mode command. This command shows the statistics for the Frame Relay PVC using MLP on a Cisco router, as shown in Example 20-2. Example 20-2. Output of the show frame-re..
