MMS Message Retries, Expiration, Conversion to SMS

Topic Keywords: operator MMSC, retry attempts, routing

There was a good simple question posted on the NowSMS Discussion Board.

We are using the MMS Gateway service. For how long does the MMS content
stays in the system?

Can we set a specific time for the message expiration?

We also use the option of converting the mms to SMS with web link. For
how long is the content stored in the platform?

As I replied to that question, I realized that there are a number of MMSC related settings that are important to operator MMSC configurations, but that are either not configurable via the NowSMS configuration user interface, or when they are, they are perhaps not very well explained.

So let me start by answering these specific questions, and then I want to expand a bit on some inter-relationship between the settings, and some other related settings.

By default, MMS mesasge content is retained for 15 days before it is expired.

To change this timeout, it is necessary to edit MMSC.INI, and under the [MMSC] section header, add DataRetainDays=##, where ## is the number of days for MMS message data to be retained by the system.

This same expiration timeout applies to messages that are converted from MMS to SMS.

A simple question, and a simple answer. Hardly worth a blog posting. However, it did get me thinking about a lot of the related configuration settings that perhaps some users don’t understand.

MMS Notification Retries

The “How MMS Works” web page is a good reference for explaining the basics of how the MMS delivery process works.

To deliver an MMS message to a client, the MMSC sends an MMS Notification message with WAP Push (over SMS in most configurations). When the client receives the MMS Notification mesasge, the client then connects to the MMSC to retrieve the MMS message content and complete the MMS delivery process.

The default settings in NowSMS assumes that the WAP Push over SMS delivery is reliable. Only one notification attempt is performed, and it is assumed that the SMSC that is responsible for delivering these notifications will queue the messages for delivery until the client is available.

In some situations this may not be a safe assumption. In these instances, the MMSC can be configured to retry these notifications to increase the probability that the client will actually receive the notification. (MMS clients will ignore duplicate notifications.)

To enable these retries, check “Retry MMS Delivery Notification”. Then specify the number of “Attempts” that the MMSC should make in retrying the MMS notification, as well as the “Delay” interval (in minutes) between attempts. Note that the MMSC will apply a progressive delay, increasing the delay with each attempt, such that the actual delay interval is the configured delay interval multiplied by the number of previous notification attempts. As an example, if “Attempts” is set to 4, and “Delay” is set to 15, the first retry attempt will occur after 15 minutes. The next attempt will occur after 30 minutes after the previous attempt, then 45 minutes after the previous attempt, then 60 minutes after the previous attempt, after which no further notifications will be attempted.

It is also possible to configure the MMSC such that it if an MMS message is not retrieved from the MMSC within a configurable timeout period, the MMSC will then convert the message to SMS, sending a text SMS message to the recipient, with a URL like that can be used from either a phone or PC browser, to retrieve the content of the message.

To enable this SMS conversion, it is necessary to define an “MMSC Routing” of the type “Convert to SMS web Web Link”.

Once that routing is defined, edit MMSC.INI, and add the following settings under the [MMSC] header:

UndeliverableRouteToSMS=VASPOutboundRouteName

This setting specifies the name of an MMSC Outbound Route that is defined in the “MMSC Routing” list, which must be of the type “Convert to SMS with Web Link”. By default, if an MMS message has not been retrieved within 120 minutes, the message will be rerouted to be sent as an SMS with a web link for accessing the MMS content.

UndeliverableRouteToSMSTimeout=####

#### is a value in minutes that changes the time period after which the UnderliverableRouteToSMS setting is applied.