Task:MMS

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** One possibility is to tag the appropiate packets with iptables and then sent to a different routing table.
** One possibility is to tag the appropiate packets with iptables and then sent to a different routing table.
** To overcome the problem with different gateways on the same subnet one could add a hard dumb route to the specific gateway via route, then set the Internet gateway to a higher priority. e.g. rename 123.123.123.0 -> MMS route via iproute2 NAT. Something like http://lartc.org/howto/lartc.rpdb.multiple-links.html maybe?
** To overcome the problem with different gateways on the same subnet one could add a hard dumb route to the specific gateway via route, then set the Internet gateway to a higher priority. e.g. rename 123.123.123.0 -> MMS route via iproute2 NAT. Something like http://lartc.org/howto/lartc.rpdb.multiple-links.html maybe?
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+
** Another solution would be a mms-fetcher-daemon running as a specific user (e.g. mmsd) and use iptables to route all these packages to the correct interface. This works around when both the GPRS and the MMSC specified is on the same IP but requires different connections. i.e. "route add 1.2.3.4 ppp:mmc - fails if there is also a server on 1.2.3.4 on ppp:normal"
 +
** '''At the core of it - whats needed is a separate interface (e.g. ppp0, ppp1 etc) for each APN the user sets up'''.
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** How to hold multiple sessions open?
* Applications should be able to request a certain IAP to be activated; thus should the MMS app be able to request the correct APN. [http://wiki.maemo.org/Mms_implemention_conversation#Higher_level_technical Source]
* Applications should be able to request a certain IAP to be activated; thus should the MMS app be able to request the correct APN. [http://wiki.maemo.org/Mms_implemention_conversation#Higher_level_technical Source]

Revision as of 13:54, 3 October 2009


Contents

Introduction

The aim of this page is to list potential obstacles and solutions in regards to implementing MMS in Maemo 5 ”Fremantle” on the N900.

Use case

While this has been discussed much back and forth both on Talk and on #maemo, here are some points why MMS should be implemeneted:

  • Quickly sending private pictures to someone.
  • While most users tend to be able to receive MMS, there's a lot few with push e-mail on their phones atm (need citation, but this is what's come up in discussion; see Mms_implemention_conversation)
  • Another use case is to send your location from nokia maps over mms to quickly allow another person using nokia maps and gps find a location or service (e.g. bar, restaurant , etc).

The advantage MMS have over e-mail on the phone as well is it's generally less spammy; e.g. no Facebook notification mails etc.

Implementation

To successfully implement MMS sending and receiving on the N900 the following has to be done:

Hooking in to the SMS receiving part and take control when the notification about MMS is received.

According to this post by danielwilms the final SDK for Maemo5 should let us do this through Telepathy. Hopefully. At least a way to handle SMS.

Fetch the MMS from the provider.

Multiple issues with this.

  • Does Fremantle currently support adding more than one APN? Someone with a device please confirm. Seems it does not.

"On the tested proto unit, connectivity options seem to be unfinished yet and e.g. there are no Internet access point settings other than Wireless LAN so I can't elaborate on the supported options and settings yet. However, even without configurable settings, the N900 automatically recognized my SIM card and set up the right Internet access point by itself." [1] "And the point is that right now, you can only define one APN in Maemo5, at least in the release I've got." [2]

  • Most operators only allow fetching of MMS when accessing via a specific APN. To access this you would have to temporarily suspend your current 3G connection and switch over to this (is this correct? need someone with knowledge on this). On S60 you won't get dropped as long as you are on a 3G connection (on the other hand this is tested with a provider who got the same APN for both Internet and MMS, only diff is different startpage - does this matter?).
  • If the user only got access to GPRS the current connection (if in-use) have to to be temporarily suspended while fetching the MMS. Can't this be solved by doing a "Deffered Retrieval" [3]
  • Accessing the MMS "server" through a specific connection: iptables tweaking? Discussion at [Mms_implemention_conversation#Technical] The following is based on that conversation:
    • The problem here is routing specific data to the specific connection. While this is possible with some clever routes, this does raise the problem with operators having the same gateway for both GPRS and MMS connections, which might lead to a collision (if both they are indeed the same gateway, it should be no problem just getting the MMS over the current connection?).
    • One possibility is to tag the appropiate packets with iptables and then sent to a different routing table.
    • To overcome the problem with different gateways on the same subnet one could add a hard dumb route to the specific gateway via route, then set the Internet gateway to a higher priority. e.g. rename 123.123.123.0 -> MMS route via iproute2 NAT. Something like http://lartc.org/howto/lartc.rpdb.multiple-links.html maybe?
    • Another solution would be a mms-fetcher-daemon running as a specific user (e.g. mmsd) and use iptables to route all these packages to the correct interface. This works around when both the GPRS and the MMSC specified is on the same IP but requires different connections. i.e. "route add 1.2.3.4 ppp:mmc - fails if there is also a server on 1.2.3.4 on ppp:normal"
    • At the core of it - whats needed is a separate interface (e.g. ppp0, ppp1 etc) for each APN the user sets up.
    • How to hold multiple sessions open?
  • Applications should be able to request a certain IAP to be activated; thus should the MMS app be able to request the correct APN. Source

Format the MMS and display it correctly.

  • How open is the Messaging client?

Plenty of open source libs to do this in other languages:

PHP1 PHP2 Java JavaSE/JavaME C Python

References

  1. My-Symbian.com PREVIEW
  2. dart45 @ talk.maemo.org
  3. Figure 7. Page 16