I just found it running and it doesn't have any dependant packages except mp-fremantle-generic-pr. What will I lose if I purge it?

It provides synchronization services for applications. For example it synchronizes IM status updates that they happen at the same time in order to save battery.

Anything else?

My guess is that it wouldn't be a problem to uninstall it. The iphb kernel module says it's a "netfilter module for delaying TCP keepalive packets".

I just did "/etc/init.d/iphbd stop" and the service stopped and removed the kernel module. Just for testing I logged on with skype, but obviously nothing special happened.

I guess if you have multiple IM services or other programs periodically sending a TCP keepalive the kernel module will take care of grouping them together.

I'll keep iphb off in my N900 (this is my primary one) and report if suddenly the neighbour's cats die or something.

Also DSME, MCE and BME daemons using it for synchronization. Maybe more user/GUI applications too.

So if you uninstall it, maybe your phone will be unbootable (dsme reboot) or in better case only some non core apps will not work...

libiphb0 is used by various Maemo programs (rss reader, modest, sip, etc.) and if you try to uninstall it it pulls basically everything with it. But it's just a lib so it can stay.

The kernel module and the daemon are IMHO safe to purge. I will actually do that once I get home so I have my spare N900 at hand. I would almost do it now on my "production" N900, but today is one of those days when I really need to be available (it's already enough that I've rmmod'ed the module and stopped the daemon .

Well, I apt-get --purge remove'd iphbd and everything seems to be still OK.

One thing to note is that after powering off and rebooting the N900 seemed to got stuck while booting. After waiting some time I pulled out the battery and tried again with the framebuffer kernel to see if I could spot where the problem was. It booted OK.

[ Note: I had only apt-get remove'd iphbd, so the /etc/event.d/ stuff was still there, even if the daemon had been removed. A cursory look at the scripts indicated no problems with that, but just to be on the safe side I did dpkg -P iphbd to remove all traces ].

Then I rebooted again to KP52 and hildon desktop came up but again Maemo got CPU-stuck. Keyboard backlight (on/off) still worked, and I did manage to turn it off with the power button (I even saw the MCE menu appear).

I happened to remember that I always wanted to remove tracker (on this particular N900), so I did, and since then I've rebooted a few times with no issues.

Conclusion: purge iphbd at your own risk. My N900s are seriously modified so there might be Maemo-stuff that breaks and I couldn't know.

For the record, I did 'apt-get remove --purge iphbd' yesterday immediately after I spotted this thread. I did not faff around /etd/init.d or anything else. The phone seemed to work fine but I did not reboot until late evening after updating KP52 modules (the reboot was not required but I did it anyway, partly to test whether removing iphbd had any effect).

As far as I can tell, my phone behaves as it has always been. No freezes on boot, no other misbehaviour. The free memory went up by about 7K.

However, reader beware! Like reinob, I have removed all that I could dare from my phone. I do not use Exchange sync (so that went too), Nokia messaging (gone)... and the only IM client I ever use is Skype, and even that only occasionally.