mozMobileConnections.length could be used for determination whether the device supports multisim or not. However it's lack of the capability of telling if the device supports DSDS or DSDA. It seems fine now because FxOS supports only DSDS at the moment so gaia could have an assumption. But if we think further and consider the gaia code extensibility, it would be great that there's an API providing the information. We could expose the information to a central API, or might need to expose the capability information to individual APIs, e.g. mozMobileMessage and mozTelephony. Filing this bug for tracking and discussion.

Yup we'll need that information when we do DSDA

I'm quite sure we can also do better APIs that would just work whether we're in DSDS or DSDA (although knowing this information would still be nice). For example: retrieving a MMS from the non-default SIM would trigger onerror for DSDS but onsuccess for DSDA, so there is no need for another API here. I bet we'll need an API for Visual things though :)

(In reply to Julien Wajsberg [:julienw] (away until March 24) from comment #2) > I'm quite sure we can also do better APIs that would just work whether we're > in DSDS or DSDA (although knowing this information would still be nice). > > For example: retrieving a MMS from the non-default SIM would trigger onerror > for DSDS but onsuccess for DSDA, so there is no need for another API here. > Indeed, current API should have responded correctly even without this. This bug is filed if gaia needs to know the capability in advance. > I bet we'll need an API for Visual things though :) Yup, agree that this kinda API definitely benefits Visual things.

Put this bug into backlog.

Firefox OS is not being worked on