Decreasing Burden on Router Resources in Unstable Unicast Routing Environment
Question
A service provider is using multicast flows to provide streaming video content to its customers.
Video streams are sometimes interrupted, and network instability is determined to be cause.
Which action should the service provider take to decrease the burden on the router resources in an unstable unicast routing environment?
Answers
Explanations
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A. B. C. D.A.
In an unstable unicast routing environment, multicast traffic can increase the burden on router resources and may cause video stream interruptions. Therefore, the service provider needs to take action to decrease the burden on router resources.
The possible actions to take are as follows:
A. Tune the RPF backoff: Reverse Path Forwarding (RPF) is a multicast routing mechanism that uses unicast routing table information to forward multicast packets. RPF backoff is a feature that allows a router to delay forwarding multicast packets to reduce the load on router resources. Tuning the RPF backoff value can reduce the burden on the router's CPU in an unstable unicast routing environment.
B. Filter unnecessary SA messages: Source Active (SA) messages are sent by routers to announce that they have receivers interested in a multicast stream. In an unstable unicast routing environment, unnecessary SA messages can increase the burden on router resources. Filtering unnecessary SA messages can reduce the number of SA messages and the burden on the router's CPU.
C. Increase the PIM hello hold timers: Protocol Independent Multicast (PIM) is a multicast routing protocol used to distribute multicast traffic. PIM hello messages are sent periodically by routers to discover neighbors and maintain multicast connectivity. Increasing the PIM hello hold timers can reduce the number of hello messages and the burden on the router's CPU.
D. Reduce the volume of query messages: Multicast routers use query messages to discover multicast sources and receivers. In an unstable unicast routing environment, the volume of query messages can increase the burden on router resources. Reducing the volume of query messages can decrease the burden on the router's CPU.
Out of the given options, the most suitable action for the service provider to take to decrease the burden on the router resources in an unstable unicast routing environment would be to tune the RPF backoff (option A). Tuning the RPF backoff value can delay the forwarding of multicast packets and reduce the load on router resources without affecting multicast traffic delivery. However, the other options (B, C, and D) can also be helpful depending on the specific scenario.
