Crawford
>> 1. Internet fax at person A dials into ISP. Gets hooked up and "online".
> 2. Internet fax A sends request for capabilities to internet fax B
> 3. Internet fax B is NOT online. Ooops. Now what
Wing
One could use SIP (RFC2543) to determine where the user "is".
Crawford
> 4. Or Internet B is online (we happen to catch it while it is dialed up),
> so Internet fax B responds with
> G3 or G4 then waits
> 5. Internet fax A now sends first page in TIFF wrapped G3 and waits for
> response
> or continues to send until the job is complete (I am not sure yet how this
> part works under IPP)
Page by page is what users expect and prefer because but for Internet transmission it's better to send a complete file.
> 6. Internet Fax B receives and sends "Okay got it" as the response.
> 7. Machines "disconnect" from each other, but may or may not hang up the
> phone line.
>> You should see the key issue is the receiving fax machine (or any
> other Internet device ) that is not full time on the network.
Couldn't agree more
Wing
Above, you're describing T.38 -- tunneling T.30 inside IP. This is
nonsense over a dialup link.
T38 may be nonsense, but not for this reason. Just depends on how long the receiving device stays connected. Plenty of individuals in the US and corporations in other countries,( too expensensive for individuals) leave dial-up connections on indefinitely.
Wing
Specifically the overhead of IP combined
with the complexities of finding the remote user's IP address make
this scenario highly unlikely.
Finding a remote user's IP Address really isn't so very difficult with the correct software at the user's end. If you operate internationaly you must consider dial-up, usually it's the ONLY scenario, and its what 70+ million fax users have today.
Wing
T.38 is defined by the ITU and is
available from http://www.itu.int
More likely is plain RFC2305-style fax -- attach a TIFF'd image to
an email message and email it.
It's OK when the sender is using email, for IFAx device to IFax you really need to get closer to T30 fax to really satisfy the users.
Crawford
> a. What do we do if Internet device B is not online at the time Internet
> device A "calls".
> b. Can a proxy of some sort (i.e. an IPP intermediate server computer (I
> didn't want to write a server server))
It can be done without a server, but it's better with one, you just need the right software
Crawford
> help resolve this issue?
> c. Do we want to instead require an IPP enabled Internet fax be online
> at all times (thereby being called a
Best not exclude the at least 50 million fax users who will not be 'online at all times' for the foreseeable future.
> fulltime fax) or are there other solutions
Yes there are other solutions
Geoff