Digital Engagement SMS Messaging Reference: Selecting the Messaging Number Type and Deliverability Factors

Selecting the Messaging Number Type

A critical aspect of your messaging strategy is determining and selecting the ideal type of number(s) for your business.  Choosing a short code or one of the many long code options will depend on answers to the messaging variables of message volume, outbound to inbound message ratios and use case(s).

The number type available, and defined associated use cases are provided in a table in the documentation below.

Availability of the different types of number are determined on a per country* basis.

SMS Overlays on Phone Numbers

Most people don’t know that SMS is actually a service that is often transmitted on a different network then voice calls. Interconnect companies keep databases of which phone companies manage which phone numbers, strictly for the purpose of routing and optimizing text (SMS / MMS) message delivery.

These databases are independent from the numbers that track your phone number for voice calls.   As the databases and networks for voice and messaging (SMS / MMS) are completely separate, messaging services implemented on your phone number will not interfere with your voice services.

Deliverability Factors:

Message Delivery Quality

There are different factors that may impact the delivery of the final destination of any SMS message.  When a message is sent from either the Salesforce's Digital Engagement platform or a customers’ device, the message is then traversing within the messaging ecosystem, a distributed design of the telecommunications industry outside the control of Salesforce influencing message delivery. Factors to be aware of:
 

Number Validity

When a number is incorrect or invalid, messages will not arrive. This is the most common reason for non-delivery.  The following are some of the contributing reasons:

• When using long codes, it may be necessary to utilize an international format and incorporate the corresponding country code.  When necessary and omitted, message delivery will fail.  
• Utilizing the incorrect country code. This is not uncommon due to the inconsistency across countries on format. Messaging within countries, such as Germany, the Netherlands and the UK, a leading 0 is added to the beginning of the number but removed when using internationally.
• Inadvertently messaging to a non-message enabled landline number.
• Messaging an enabled landline to a non-supported device.
• Invalid numbers, whether through users changing carriers, getting new devices or just from being mistyped.

Carrier Filtering

Please refer to Carrier Filtering for a better understanding of the primary reasons message filtering is in place.  In addition to the primary reasons discussed in that section (adhering to rules, regulations and compliance requirements within target markets and protecting the end subscriber) there are other factors related to filtering that affect the deliverability of messages.

• There are some countries that forbid messaging during a specific time period (no messaging between 9.00 pm - 9.00 am in India) and will block any messaging within that window.
• Some countries institute a “Do Not Deliver” list.
• Messages could be filtered due to the destination device (e.g. no network capability, connectivity issues, unsupported device, inability to render special characters, memory full).
• Encoding utilized for message delivery may not be supported by local carriers (e.g. unicode, message concatenation, MMS).
• Roaming and/or out of the reach of the carrier, the carrier has limited or no “store and forward” capability, or the subscriber reach only becomes available post the message being discarded due to surpassing a ‘holding’ limit.

Routing Factors

Messaging can traverse a myriad of routes for delivery to the device, yet not all routes perform the same.  Some of which result in high delivery, where others may result in latency, and even possibly non-delivery. 

• Salesforce works with Tier 1 providers, mitigating points of failure and possible filtering, which accounts only for the initial connection route.
• Local Number Portability (LNP) is in place for users to change (port a number) from one carrier network to another.  There are many safeguards for LNP employed by carriers and aggregators, such as network look-ups and updates to databases in real time. 
• However, the mobile carrier market is dynamic and distributed whereas these safeguards, functionality and even databases are not always available in some countries resulting in incorrectly routed messages.
• Additional safeguards are in place to help mitigate issues resulting from countries lack of or limited accessibility to LNP functionality (e.g. prefix routing), but new telephony prefix ranges are sold regularly where it is not always possible to ensure updates across all countries in a timely manner.  
• Prefix routing can only help in countries where prefixes are kept up-to-date.
• Routing can also be impacted when a carrier or provider downstream changes routing for varied reasons; bad behavior of another (e.g. spammers, lack of compliance on line type, etc), basic maintenance and/or the attainment of new routes to accommodate additional reach.  

The downstream changes may inadvertently impact the delivery path of upstream message providers until such time one/many identify and correct it directly with the initiating party, or make changes (by the individual upstream provider) for a new message delivery routing path.