I am struggling to see why BT would throttle uploading on torrents other than as a measure to restrict filesharing of copyright material. Or do BT have upstream capacity issues somewhere (which would seem unlikely when selling async broadband services as by far most demand be on downstream). But consider that BT also sell other types of services as well which could make that situation possible.

Is there limitations on capacity for upload traffic somewhere on FTTC infrastructure?

BitTorrent upstream consumes loads of bandwidth.

http://torrentfreak.com/bittorrent-traffic-increases...

In reply to a post by Zadeks:

BitTorrent upstream consumes loads of bandwidth.

http://torrentfreak.com/bittorrent-traffic-increases...

but not as much as downstream.

More than downstream.

On a fast connection a download won't take very long at all and will only consume a relatively small amount of bandwidth. If the download is left seeding 24/7, it'll consume way more upstream bandwidth than down.

180GB uploaded per day is easily doable.

In the newest Huawei MSAN controllers, the fibre uplink is asymmetric. Downstream and Upstream are duplexed across two wavelengths on a single-mode fibre. TX (upstream from MSAN to exchange) has a capacity of 1.244Gb/s whereas RX (downstream from exchange to MSAN) is 2.488Gb/s. The MSAN can accommodate two small form-factor pluggable (SFP) optical transceivers, so several fibres can be 'cascaded'. However, statistical multiplexing and traffic management must still be used. (Up to ) 192 subscriber lines multiplexed over two 1.244Gb/s fibre links means a maximum upstream of 13Mb/s per line.

See: http://www2.picturepush.com/photo/a/11358865/1024/Hu...

cheers, a

you forget all the users who dont use torrents, their collective downstream usage is more than torrent's upstream usage.

Of all the isp's data graphs I have seen I have never seen one with more upstream usage than downstream.

Whilst 180gig a day is doable, in practice dont assume every torrent user will upload that much.

In reply to a post by asbokid:

In the newest Huawei MSAN controllers, the fibre uplink is asymmetric. Downstream and Upstream are duplexed across two wavelengths on a single-mode fibre. TX (upstream from MSAN to exchange) has a capacity of 1.244Gb/s whereas RX (downstream from exchange to MSAN) is 2.488Gb/s. The MSAN can accommodate two small form-factor pluggable (SFP) optical transceivers, so several fibres can be 'cascaded'. However, statistical multiplexing and traffic management must still be used. (Up to ) 192 subscriber lines multiplexed over two 1.244Gb/s fibre links means a maximum upstream of 13Mb/s per line.

See: http://www2.picturepush.com/photo/a/11358865/1024/Hu...

cheers, a

ok thanks so at least one reason why its done then.

Other traffic is irrelevant. I was explaining the reasoning behind the throttling. 180GB might be a lot, but it doesn't take long to seed multiple copies of a high definition film.

In reply to a post by Zadeks:

Other traffic is irrelevant. I was explaining the reasoning behind the throttling. 180GB might be a lot, but it doesn't take long to seed multiple copies of a high definition film.

its relevant because we are talking about overall capacity to shift data, so if more downstream capacity is needed then that in turn increases upstream capacity.

Without traffic shaping in place, P2P traffic will always consume more upstream bandwidth than down, demonstrated by the TF article.