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Traffic Types

Comparing Traffic Types

In today’s current mobile ecosystem, there are two categories of messaging traffic. A2P is geared toward business and promotion while P2P caters to personal communication-oriented use cases.

Although both A2P and P2P traffic deliver SMS, they are treated separately within the mobile messaging ecosystem and differ in their:

  • Service plans and fees
  • Intention and uses
  • Carrier reach*
  • Bandwidth and throughput rates
  • Source addresses (the “from” number or name)
  • Regulations and restricitons

*An A2P route may not reach the same carriers in a given country that a P2P route reaches

Long codes may either be enabled to support messaging globally or limited to messaging within the country of the registered code. The latter variety is referred to as a “Local Long Code.” Aerialink supports both types of long codes, utilizing A2P routes for non-US Local Long Codes and P2P to deliver messages from US-registered long codes globally.

Shared Characteristics

Although P2P and A2P differ in multiple ways, they do share a few key characteristics.

For instance, messaging regulations and restrictions are usually defined the country where the message terminates. (e.g. A2P traffic sent from a US-registered number to a mobile number in South Africa is subject to South African restrictions.)

Furthermore both messaging types can also be restricted by carrier blocks intended to minimize SPAM. However their blocking thresholds differ. While North America maintains notably tighter blocking restrictions when compared to other countries, carrier filtering is increasing globally in an effort to block traffic from entities that do not have contractual agreements with wireless operators.

About A2P

A2P or “application-to-person” utilizes applications or systems to send messages. It is the traffic type on which all short codes operate and can be used for both one-way and two-way message delivery. Applications are able to send high-volume one-way messages in bulk, thus distributing one message to many users in a single burst. This capability has earned A2P traffic the nickname “bulk messaging.” It is commonly used by financial institutions, airlines, hotel booking sites, social networks, and other organizations sending SMS from their systems to their customers.

Delivery Direction

The options listed below describe the availability for A2P SMS via routes both within North America (country code +1) and internationally (outside of country code +1):

  • 1-way International*
  • 2-way North America
  • 2-way International

\1-way A2P is not supported in North America due to handset opt-in requirements.*


A2P messaging is best for use-cases which require asymmetrical traffic, as it was designed specifically to allow the outbound-to-inbound messaging ratio to exceed 1:1 without concern.

Regional Restrictions

North America

A2P messaging in US and Canada is restricted to certified short codes and the 8XX Plus Route. The route must support two-way messages to enable text-based consent from mobile end-users.


Countries outside of North America allow a variety of sender IDs to route A2P traffic:

  • Long Code
  • Short Code
  • Alpha or Alphanumeric Sender

Depending upon the configuration of an international route, A2P may be set for one-way (outbound only), or two-way (outbound and inbound). There are some destinations where a source address may not “stick” and gets replaced for optimized delivery, which causes the message to arrive with a sender ID differing from the original Sender ID. In these cases, inbound SMS would not be available.

Some countries allow non-marketing, A2P messaging to be pre-approved with a registered Alpha sender. Aerialink can submit requests with sample messages from customer programs to enable pre-registration.

Volume & Throughput

A2P does not restrict message volume, but carriers do place limits on throughput. Default messages-per-second is set to 10 on the Aerialink Gateway.

About P2P

Two-way, P2P traffic was originally created as the standard form of consumer SMS, used to transmit messages between two mobile users. However, despite the fact that P2P stands for “peer-to-peer” or “person-to-person,” it does support traffic between an application and a person provided that the message is initiated by a person as opposed to a system.

A mobile user can identify the sender of a P2P message by the mobile number displayed in the “from” field on their handset. When an application sends an SMS, the sending phone number is called a long code. A long code is essentially a registered phone number that supports SMS. Person-to-Person traffic may be sent using a long code. Messages may originate from mobile phones, computer applications or internet-based services but the message must have been initiated by human interaction. P2P messaging does not require carrier certification. Even so, it is highly regulated to restrict misuse such as SPAM and bulk messaging. Carriers have put sophisticated filters on their networks to block suspicious messaging. From time to time, these programs may block legitimate P2P messaging, but this is the exception and not the rule. All P2P messaging programs that run through Aerialink require our approval, and resellers are responsible for vetting their customers’ programs.

Delivery Direction

The options listed below describe the availability for P2P SMS via routes both within North America (country code +1) and internationally (outside of country code +1):

  • 2-way North America
  • 2-way International


Sending messages via P2P is best for content providers who wish to have a reciprocal messaging style with their end-users, or initiate content from one user to another.

Regional Restrictions

North America

US and Canadian P2P routes have the following restrictions:

AttributeRequirement or best-practice recommendation
Balance1 outbound : 1 inbound
Sender ID+1 country code long codes. Codes cannot be changed; spoofing is against regulation.
Throughput1 msg / 2 seconds
VolumeMaximum 300 msgs/day/code
Max 10 destination mobiles per code per transaction
FrequencyRandomized time intervals or user-triggered sends
LengthShort messages recommended.

If your core SMS content is generated by a system rather than manual entry by a person, then your program is “Automated.” Automated programs require user consent via an opt-in process. If your application interfaces with Aerialink via our API, the opt-in process should be handled by your application.

Aerialink customers are prohibited from sending unsolicited messages containing advertisements, promotions, tips, marketing and other content to a recipient without the end-user’s express and direct prior consent. This rule is driven by the FCC Telephone Consumer Protection Act (TCPA), whose objective is to “drive spammers out of the marketplace to protect wireless consumers from unwanted text messages.”

This rule also obligates content providers who utilize automated messaging to obtain and maintain proof of end-user consent. Records should be kept for a minimum of five years from the most recent date of consent.

User Opt-Out

All senders must honor end-user opt-out requests wishing to cease reception of future content, and do so as instantaneously as possible.

We highly recommend that you implement industry best-practice keywords, HELP and STOP and their associated auto replies. Aerialink provides “enforced opt-out” which blocks outbound messages from a long code from which a user has opted out.