Can't connect to more than 15 peers

[Headcase_Fargone]

Hi all,

I recently installed Transmision 1.7x on my NAS and I've got most everything working the way I want it despite my Linux ineptitude. The only thing that I can't seem to fix is the peer max. No matter what, Transmission will NOT connect to more than 15 peers per torrent.

I've edited my settings.json file (while transmission-daemon was stopped) to the following:

"peer-limit-per-torrent": 200,

Right-clicking and bringing up Properties of a torrent in Transmission Remote I see that Maximum Torrents now defaults to 200. It still refuses to connect to more than 15 per torrent, resulting in extremely slow downloads.

Any ideas?

[Headcase_Fargone]

Something I just noticed...

In the Transmission Web Interface this torrent shows "Downloading from 18 of 85 peers." However, in Transmission Remote I see 85(18) under SEEDS. The Leechers column in Remote shows 1090(15). This is what I want to break 15.

I'm very confused at this point.

[Headcase_Fargone]

Seriously? 15 connections for downloading with no way to change that? I'm currently downloading at 10kB/sec on a torrent with 1100 peers. If there's no way around that limit Transmission seems kind of... well, pointless.

Can anyone verify this?

[rb07]

The limits can be changed but there are more than one limit in the picture.

You have your (from transmission-remote -h):

Code: Select all

  -pr  --peers                  <max>                Set the current torrent(s)' maximum number of peers each
  -gpr --global-peers           <max>                Set the global maximum number of peers

This parameters should be set depending on how many torrents you want to keep active, since global-peers/peers by default is 240/60 you're fine with 4 or less active torrents. Recommendations point to using a low peers limit since using higher values could trip a problem with your gateway (to many open connections and the throughput goes downhill because the gateway just can't handle it -- it varies with the hardware, and software on the gateway).

And from those connected there is something you can't control, which peers want to let you download, for instance:

You see all those lowercase "d" on the Status column? Those are peers that are not allowing you to download, for now, that's one reason you see 60 connected but only 15 downloading. Transmission is smart enough to discard "lame" peers (my term for those that just connect and do nothing, which is quite common), you only see all those "d" because at some time they did allow you to download and probably will allow later... just the way this works.

Finally there is settings with upload/download speed limit, usually unlimited download and 80 to 90% of your nominal (what your ISP says you have) upload speed work fine. If you set upload to unlimited, it usually causes problems, the download connections require a bit of upload to acknowledge received packages, and to communicate with tracker, PEX and DHT if used, this last one DHT is said to use more bandwidth (but that may have been for an older version of the protocol).

There's a lot to experiment with and no real formula to optimize things.

[Headcase_Fargone]

I understand all of that, but I still don't get the 15 peer limitation. I can load this exact same torrent with 1100 peers in the swarm into uTorrent and easily reach 300kB/sec from over 100 peers, whereas I'm seeing at the very most 50kB/sec in Transmission. That's usually more like 10kB. My DIR-655 router has always been more than up to the task for torrenting, so I know that's not it.

Is there no way to change that 15 peer limit? It doesn't help to change the per torrent cap to 20 or 60 or even 512 if it never downloads from more than 15 at a time despite being connected to more. Or am I still missing something here?

Thanks for the input so far, by the way.

[rb07]

There is no 15 peer limit, just move the --peers parameter and see how it changes. I see you said you already tried, but did you wait to see it change? it takes time. BTW I agree that Transmission seems to spend most of the time with 15 active peers, I don't really know why that is, but I've also seen it using more, that's why I say there is no limit.

The speed in not a function of the number of peers, as somebody already said, you could saturate your capacity with only one peer if, and only if, that peer can and is willing to download at (your) full speed; yes, I've also seen that happen (that's usually the big difference when you use private trackers).

[rb07]

Look :

There's no limit, that server is running with default values. The big difference is the torrent, it is being served by a private tracker.

[Headcase_Fargone]

Look :
There's no limit, that server is running with default values. The big difference is the torrent, it is being served by a private tracker.

This same torrent hits 600kB/sec in uTorrent. It has yet to break 100kB/sec in Transmission. This can't possibly be normal. Just look at the number of seeds. Surely I have something set wrong.

[Rolcol]

The peer limit is really a number of upload slots. Upload slots limits how many peers you will upload to so that each peer has a higher speed than an uncapped connection. These upload slots don't affect how many you download from. If you want to mess with it, its settings.json entry is:

Code: Select all

    "upload-slots-per-torrent": 14, 

uTorrent announces to multiple trackers at once and therefore has a better pool of peers to choose from which could explain its download speed. Transmission 1.80 will include this type of announcing.