What information is given to the trackers during an announcement?

[houseonfire]

I know it sends the total upload amount and the total download amount at each announcement. Is there anything else it sends that corresponds to the ratio stats or the seeding time? Like does it send total time the torrent has run for or does the tracker determine this by counting the number of announcements?
Some more things I don't know:
1) Is 'update' and 'announcement' the same thing?
2) Is there an automatic announcement when a torrent download reaches 100% irrespective of the next announcement time? Does this announcement include some special entity or is this just a regular annoucement but with %done = 100% ?
3) Is there an automatic announcement when I stop the torrent in the client? I have read many times to 'stop the torrent before update' but never understoood what it means. Again does this annoucement include any speical entities or is just a regular annoucement?
4) Which values get reset when the torrent is stopped?

Help me please!

[bjs]

BitTorrentSpecification - TheoryOrg

Or google "bittorent protocol".

[anon]

I know it sends the total upload amount and the total download amount at each announcement.

Don't mean to be a bitch, but the right term is announce.

does it send total time the torrent has run for or does the tracker determine this by counting the number of announcements?

Trackers can easily know the total time by adding the distance between announces. If you've 'started' the torrent, then sent regular announces every 30 minutes for the last 19 hours, it's safe to say it's been running just as long.

Some more things I don't know:
1) Is 'update' and 'announcement' the same thing?

The way it's used here, pretty much yes. In case you care, make a distinction between regular "updates" that let the tracker know how you're doing, and "announces", which are just the means to report that information.

2) Is there an automatic announcement when a torrent download reaches 100% irrespective of the next announcement time?

Yes.

Does this announcement include some special entity or is this just a regular annoucement but with %done = 100% ?

It sends the 'completed' event in addition, which is ordinarily a one-time thing.

3) Is there an automatic announcement when I stop the torrent in the client?

Yes.

Again does this annoucement include any speical entities or is just a regular annoucement?

It sends the 'stopped' event. Usually the numwant will be zero here, as the client has no need for peer IPs.

4) Which values get reset when the torrent is stopped?

'uploaded' and 'downloaded' for sure. Clients that generate a new peer_id and/or key will do just that next time you start the same torrent. Other clients sending nonstandard parameters may also reset them accordingly if necessary.

The best way to know "what X sends to Y" is to run a packet sniffer and see by yourself.

Help me please!

I think I posted bjs' link many times in this forum.

[houseonfire]

Thank you very much for the link bjs. But in that wiki, there is nothing about the total time the torrent has run. So, does the tracker calculate it by counting the total number of announcements?

And I found this in that page.

ip: Optional. The true IP address of the client machine, in dotted quad format or rfc3513 defined hexed IPv6 address. Notes: In general this parameter is not necessary as the address of the client can be determined from the IP address from which the HTTP request came. The parameter is only needed in the case where the IP address that the request came in on is not the IP address of the client. This happens if the client is communicating to the tracker through a proxy (or a transparent web proxy/cache.) It also is necessary when both the client and the tracker are on the same local side of a NAT gateway. The reason for this is that otherwise the tracker would give out the internal (RFC1918) address of the client, which is not routable. Therefore the client must explicitly state its (external, routable) IP address to be given out to external peers. Various trackers treat this parameter differently. Some only honor it only if the IP address that the request came in on is in RFC1918 space. Others honor it unconditionally, while others ignore it completely. In case of IPv6 address (e.g.: 2001:db82::100) it indicates only that client can communicate via IPv6.

Does this mean, they can see my ip even if I'm announcing through a proxy? So the only way they won't see the external ip is with a vpn?

Thank you very much anon for the detailed info. Seems our posts crossed so, couldnt see your post before making mine. And your post already answers the question on the total time.

[anon]

And I found this in that page.

Does this mean, they can see my ip even if I'm announcing through a proxy? So the only way they won't see the external ip is with a vpn?

'ip' is an optional, custom parameter that is almost never used or even taken into consideration by the tracker. You use a proxy, they see a proxy IP.

[Jordan]

Can you also tell what happens when there is a power outage and internet gets disconnected without stopping the client?

[anon]

Can you also tell what happens when there is a power outage and internet gets disconnected without stopping the client?

The tracker won't be notified, obviously. The torrenting "session" will remain open. When you restart your client, it should reannounce itself with a different peer_id and key, and create another one. Trackers run a cleanup script regularly (usually every 30-60 minutes) to remove sessions whose updates are long due, so after an hour at most everything will be fine.

[houseonfire]

So when the tracker is down or there is a loooong power outage, seedtime is lost, right or does client tell the tracker there were x number of failed announces and it calculates accordingly?
If I manually force announce a few times, does my seedtime increase dramatically or does tracker only consider those announces for seedtime calculation which were x minutes after the previous one?

[shoulder]

If I manually force announce a few times, does my seedtime increase dramatically or does tracker only consider those announces for seedtime calculation which were x minutes after the previous one?

No, it won't increase.
Normally a tracker saves a timestamp of your last announce, and adds the difference to it.

[anon]

So when the tracker is down or there is a loooong power outage, seedtime is lost

The way most trackers work, you won't lose the amount of seeding time you had accrued until the outage/problem.

If I manually force announce a few times, does my seedtime increase

As I like to say, you can fake the "seed", but not the "time"