[ntpwg] KoD 'backoff' BCP/direction

[Danny Mayer]

Harlan Stenn wrote:
> The draft says:
> 
>    a.  For kiss codes: DENY, RSTR the client MUST demobilize any
>        associations to that server and stop sending packets to that
>        server;
> 
>    b.  For kiss code: RATE the client MUST immediately reduce its
>        polling interval to that server and continue to reduce it each
>        time it receives a RATE kiss code.
> 
>>From my POV this is almost helpful.
> 
> For case (a), for what duration SHOULD the client demobilize and stop
> sending packets to that server?
> 

Indefinitely. It should never try and contact that server again.

> For case (b), are there any recommendations on how much the client
> SHOULD reduce the rate at which it is polling the server?
> 

No. It was deliberately left vague. It's hard to decide that question. I 
would recommend backing off by doubling the interval between polls every 
time one of these packets is received.

> In case (b), do we mean 'polling rate' (or frequency) instead of
> 'polling interval'?
> 

Yes, that's an error on my part. Thanks for catching it. It should be 
reduced frequency.

> Is there an easy way the server could 'offer a suggestion' in either of
> these cases?  What are the costs/benefits to having the server offer
> ideas on these rate limits instead of relying solely on the client?

The server can never really make recommendations. That's up to the 
implementation, dependent on requirements. Saying "back-off" should be 
enough for the client to take the appropriate action.

Danny