Re: [Lsr] Flow Control Discussion for IS-IS Flooding Speed

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Les,

> As you need to send signaling based upon dynamic receiver state and this signaling is contained in unreliable PDUs (hellos) and to be useful this signaling needs to be sent ASAP - you cannot wait until the next periodic hello interval (default 10 seconds) to expire. So you are going to have to introduce extra hello traffic at a time when protocol input queues are already stressed.


I am not proposing that we add additional packets at this time.  Yes, I realize that it may limit the effectiveness of the feedback, but without serious experimentation, the cure may be worse than the disease.  I propose to tread very carefully.


> Given hellos are unreliable, the question of how many transmissions of the update flow info is enough arises. You could make this more deterministic by enhancing the new TLV to include information received from the neighbor so that each side would know when the neighbor had received the updated info. This then requires additional hellos be sent in both directions - which exacerbates the queue issues on both receiver and transmitter.


I am not proposing this.  If the hello is lost, then the transmitter has less information to work with, which is not an unreasonable situation.

Tony