In reply to a post by WWWombat:

The OP isn't reporting a problem on one protocol - and actually fails to tell us what NNTP behaviour is seen.

Depends how you take what was posted. "8MB/s on a download and 5MB/s on supernews", sounded like one protocol to me, being the latter.

Discounting the latency as that can happen for many reasons when pushed. It could even be a dodgy router not able to cope with multi threaded applications. Of course, thats based on the assumption that the other download at 8MB is single thread as is common for a download (gone are the days of things like GetRight, although i'm sure someone still uses it, somewhere) and the NNTP data is multi thread.

We've seen an increase in routers that have QoS/bandwidth management enabled by default, or when manually enabled the defaults are not great causing very odd behaviour.

Matt

It's OK this evening.

I'm monitoring from an iMac connected via Ethernet directly to the router.
The news service is being done on a FreeBSD box connected, via powerline, to the router.

What I was noticing that evening was that when the NNTP client was switched on, and approx. 10 concurrent NNTP connections were ongoing, the combined NNTP download rate was about 500KB/s. Other times, the download rate is in excess of 5MB/s, close enough for me to line rate to not worry about it.

I was pinging a remotely hosted server during this process and observed a pretty consistent 12ms ping go up to 1200-1500ms until the NNTP client was disabled.

During this time all clients (wired/wireless) suffered; I noticed that my Sonos radio stream almost immediately stopped, and browsers on all clients took much longer to load pages.

At the same time of day (with NNTP client disabled), a HTTP download from the iMac or from another Windows PC on the same Powerline 'segment' consistently showed about 7MB/s download rate.

I think I might try moving the NNTP client box so it's directly connected to the router and see if the problem goes away, although I have no idea how Powerline could cause such an issue in this scenario. The ASUS router CPU load doesn't exceed 10%. No QOS is enabled on it.