The reason I’m asking is because iMessage has been down for a most of our customers. We routinely send messages 500-700 characters long and have zero problems over iMessage. Now that we’re sending them via MMS, one of two things happens:
1) The message gets “undelivered” 5-7 times (takes 15-30 seconds each attempt)
2) The message will go through on it’s first attempt
I’m curious what’s actually happening with an MMS and why most of the time it takes 5-7 times to get delivered and seems to shut down the “messages” app for 30 seconds each time. Also, why after 7 attempts will it suddenly deliver in 3 seconds after I hit send?
iMessage has been having problems since Wednesday and since this is happening all day, I’m genuinely curious why regular long messages get constantly rejected, and only after 7 attempts will the phone actually “deliver” the MMS messages.
Sorry if the terminology is wrong.
In: 14
SMS is a technology that’s built on a basic function of voice networks that’s been around for 20+ years. It’s limited to 140 text characters, no emojis. Some phones in the mid-2000s were smart enough to break large SMS messages into 140 character parts, send them one by one, and reassemble it into a single entry.
MMS is a cross-network thing supported by the wireless carrier and their data network. Agreements were made on picture/video encoding and those standards were programmed into phones. Since it was on the data network there were fewer limitations, long messages, group messages, and emojis were possible.
iMessage is an MMS that uses your AppleID for delivery, and the app supports falling back on the SMS/MMS technologies if the user isn’t an iMessage subscriber. There’s even more functionality than MMS because it’s only used on Apple products, so no carrier agreements.
Google has a competing open standard called Rich Communication Service. In the last couple years you may have noticed the behavior of an iMessage user liking an android user’s text messages – You used to get a separate message saying someone liked your message. Now the message gets the thumbs up icon. It’s likely that Google is adopting some of the standards of iMessage.
I cannot send or receive MMS messages with my Cell plan. SMS only. I can receive IMessages as they are not through the cellular network.
MMS messages are downloaded from your carrier’s MMSC via the the carrier’s gateway, referred to as the WAP gateway in ye olden days. This is part of the MM1 interface, and delivers the message content which may consist of multiple parts (text, video, audio, images, smil aka presentation layer) encoded in a format your phone’s messaging application understands – basically a condensed form of MIME as used for email.
The SMIL presentation layer, if present, tells the messaging app how to present the content to you, e.g. show image 1 for 20 seconds, followed by image 2 for 15 seconds while playing this audio, for instance. Modern messaging apps don’t tend to support SMIL very well, if at all. It’s a holdover from the days before smartphones.
In order for your phone to know that there is an MMS waiting to be downloaded, the MMSC sends a specially formatted SMS via the SMSC to your handset. This specially encoded “WAP Push” SMS contains, among other pieces of information, the URL of the waiting message and the so called “port” for MMS messaging (a specific integer value). This is how the phone’s OS knows that this SMS is an MMS notification, and not a regular text message SMS.
The MMS taking multiple attempts to deliver is just your carrier’s infrastructure for MMS being overloaded or bad. Well maintained MMS infrastructure is every bit as reliable as the SMS and mobile data network services, and depend directly on these. MMS has not been a priority for most carriers for at least a decade.
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