Leveraging weblogging, Trackback, XML/RPC

[Steve Dodd]

Some random thoughts of mine.

Many people are getting used to communicating via weblogs, so a system
where they store their own outgoing mails and send notifications may not
seem so alien to them.

There's a system built on top of XML/RPC (or SOAP, can't remember which,
and not an expert in these things) called "Trackback", which is used at
the moment for notifying a web server that someone has linked /
commented on a blog entry. Could this be leveraged to provide
notifications for an IM2000 style system?
<http://www.movabletype.org/trackback/beginners/>

[James Craig Burley]

Post by Steve Dodd
Many people are getting used to communicating via weblogs, so a system
where they store their own outgoing mails and send notifications may not
seem so alien to them.

Yup, that might be a new-school/old-school kinda thing, so im2000
might well fit right into a new, growing audience that has different
expectations.

[James Craig Burley]

Post by Steve Dodd
There's a system built on top of XML/RPC (or SOAP, can't remember which,
and not an expert in these things) called "Trackback", which is used at
the moment for notifying a web server that someone has linked /
commented on a blog entry. Could this be leveraged to provide
notifications for an IM2000 style system?
<http://www.movabletype.org/trackback/beginners/>

Is it illustrative that many of that page's links to posts don't work
(starting at <http://www.movabletype.org/trackback/beginners/#729>)?

To me, a broken link is a broken link, which probably relates strongly
to why I prefer push delivery to pull for emails.

But maybe the blog community takes broken links fully in stride,
treating them as "oh well, guess so-and-so didn't think what he had to
say was important enough to leave posted for this long", if even
considered to that extent?

[Clemens Fischer]

Post by Steve Dodd
There's a system built on top of XML/RPC (or SOAP, can't remember which,
and not an expert in these things) called "Trackback", which is used at
the moment for notifying a web server that someone has linked / commented
on a blog entry. Could this be leveraged to provide notifications for an
IM2000 style system? <http://www.movabletype.org/trackback/beginners/>

But maybe the blog community takes broken links fully in stride, treating
them as "oh well, guess so-and-so didn't think what he had to say was
important enough to leave posted for this long", if even considered to
that extent?

i'm a supporter of im2k getting negotiation features for various reasons.
your estimate of some users interpretation of a broken link should be a
configurable behaviour.

i also believe it should well be possible to have SMTP and IM2000 to
coexist. think of anonymous POP/IMAP servers to offer mailinglist traffic
(no special subscription neccessary for read-only access) and leave it at
that until the IM2000 specification has matured.

clemens

[Lester Vecsey]

--
How should messages be identified? How should messages be downloaded?
Messages could be retrieved through HTTP, but an NFS/FSP-style UDP-based
protocol would be much more resistant to denial of service.
--

The page also brings up questions about how messages should be identified. I
would like to see a few of us spec out an example udp packet layout that
would for initial test purposes just include a small identity number such as
size 32 bits that points to a unique message on that server, followed by a
single byte that the client could set to a command that represents ``get'',
and optionally followed by a byte range for the portion of the message to
retrieve. The first packet returned from the server would tell the client if
the message of requested identity number exists, and it'll include the size
of the message along with the start of the message content. The client would
have to acknowledge that it received the data by requesting the next range.
Client backoff policy would be incorporated here, so if the client doesn't
hear from the server after 4 seconds, it'll still send another range request
and can increment a counter but if it doesn't hear back again it'll wait 16
seconds before sending again, and so on.

A few of us would come up with these test servers and put some messages in
them, and write clients to talk to them, basically a set of unix utils that
talk to the server, and also an smtp or pop3 front end so you can put this
in front of Outlook express to send and retrieve messages that way too. You
could run the front end under daemontools on a unix machine for your
network, or, a small windows binary using mingw could be built for strictly
windows users that want to run this entirely on their own windows machine or
windows network. In either case, Outlook express talks to the front end,
which in turn does the real communication with the udp based im2000 server.

Now, is anyone here familiar with Bit Torrent?
http://bitconjurer.org/BitTorrent/

I wonder if the UDP based denial of service resistance could be taken a step
further using the techniques mentioned in the BitTorrent paper.
Specifically, this would be very useful for the case of a mailing list with
many people retrieving the same daily message as the load would be
distributed without a single point of failure.

Lester

[l***@maths.uq.edu.au]

Post by Lester Vecsey
--
How should messages be identified? How should messages be downloaded?
Messages could be retrieved through HTTP, but an NFS/FSP-style UDP-based
protocol would be much more resistant to denial of service.
--
A few of us would come up with these test servers and put some messages in
them, and write clients to talk to them, basically a set of unix utils that
talk to the server,

I have recently gained access to a UML (user-mode Linux) hosting service and
would be willing to donate a portion of its capacity/bandwidth for a testbed.
For those of you not familiar with UML, it is basically a kernel that runs in
user space, and allows multiple incarnations on a single physical box
(frequently used in honeypot traps). We can attempt to simulate traffic flows
between several virtual mailstores, even implement different protocols to
evaluate which are the common features (which goes into a RFC) and which can be
specific implementations (for those inclined to wander down the
commercialisation path).

The only sticking point is that it will have to comply with the Australian spam
legislation (which IMHO actually maps nicely onto IM2000 as it requires
authorisation before any actual sending).

Lawrence

[Clemens Fischer]

Post by Lester Vecsey
Now, is anyone here familiar with Bit Torrent?
http://bitconjurer.org/BitTorrent/
I wonder if the UDP based denial of service resistance could be taken a
step further using the techniques mentioned in the BitTorrent paper.
Specifically, this would be very useful for the case of a mailing list
with many people retrieving the same daily message as the load would be
distributed without a single point of failure.

for mailinglists this sort of "P2P" concept would work, but you still need
to provide consitency. every user wants to see *all* messages, even when
his peer didn't have the complete set.

for private emails, people would have to use end-to-enc encryption to keep
privacy.

clemens

[Jonathan de Boyne Pollard]

LV> [<URL:http://cr.yp.to/im2000.html>] also brings up questions
LV> about how messages should be identified.

<URL:http://homepages.tesco.net./~J.deBoynePollard/Proposals/IM2000/djb-answers.html>

LV> would like to see a few of us spec out an example udp packet
LV> layout that would [...]

<URL:http://homepages.tesco.net./~J.deBoynePollard/Proposals/IM2000/Architecture/#Protocols>

LV> [...] an smtp or pop3 front end so you can put this
LV> in front of Outlook express to send and retrieve messages
LV> that way too.

<URL:http://homepages.tesco.net./~J.deBoynePollard/Proposals/IM2000/shims.html>