>
> NCF maximum latency . . . the time the product spends on queue at the NCF
> uplink . . . was 62 seconds since 2 Feb. Average has been 2 seconds on the
> NCF NWSTG queue. This is quite good . . . especially considering latencies
> on EMWIN is upwards of 15 minutes for "emergency" products, and hours for
> imagery. Also, since the first of the year, the NWSTG traffic has exploded
> from a little over 4GB per day to 5.9GB per day (O.K. - let's just call it
> 6GB per day) - 50% increase.
>
> Amount of time a product spends on a "queue" after downlink is vendor and
> location specific.
>
----------
>
> IDD latency will undoubtedly be landline (internet) or IDD receive system
> related.
Emwin uses a priority queueing system. Severe and Tornado warnings get
queued in front of everything. Imagery and graphics get dead last and only
get sent after everything else, IF there is time.
The traffic rate is highly variable. Graphics often get dumped since they are
so much larger than text products.
15 mins would effectively render emwin down. TV, radio, Police, and numerous
emergency management agencies utilize emwin to receive real time warnings. Ive
never seen a 15 min queue on warnings. The whole purpose of emwin is to enable
fast low cost disemmination of warnings to emergency personell. I don't think
its a good example to compare latency against due to the queuing.
Ray Weber
MA Skywarn
