SMS messaging industry has been experiencing exponential growth of SMS fake delivery routes in the recent years. This is by far the most serious threat to the quality of SMS delivery and the most affluent source of revenue for the companies which generate them. Fake delivery receipts are very hard to detect and at times almost impossible to eliminate completely.
There are two main sources and causes of fake SMS DLR receipts, namely MNO and SMS aggregator caused fake DLRS, which I will try to examine and propose my solutions and tips.
AGGREGATOR CAUSED FAKE DLRS
Generation of fake delivery receipts does not cost any money. There are several SMS aggregators which got highly attracted to the idea of 100% margin and easy money. There is a number of approaches which such aggregators tend to take:
In order to overcome fake DLR issue caused by SMS aggregators, one should perform thorough SMS Gateway testing on real handset test number in order to verify delivery.
Cause 1. Fake delivery receipts which affect all traffic. This is the most primitive approach and nowadays it is rarely used.
Solution 1. Since fake DLRs affect all SMS traffic, it should be quite easy to detect by sending a test sms to a mobile test number, either your own or via 3rd party service provider, such as TelQ Telecom. You need to simply send a test message and verify real delivery.
Cause 2. Fake DLRs which affect all traffic besides whitelisted SMS test numbers.
Solution 2. In order to avoid your testing number getting whitelisted, it is suggested not to escalate fake DLR message examples to untrusted partners because sooner or later they will end up whitelisted. If possible, it is suggested to use several SMS test number providers (especially if you don’t have to commit).
Cause 3. Certain aggregators may give fake delivery reports exclusively on bulk traffic, hence separate tests even on non-whitelisted test numbers would not help.
Solution 3. You may want to send a small trial campaign to a few dozens of numbers, one of which would be your mobile test number.
Cause 4. At times you may encounter instances of fake delivery receipts to a random % of your traffic. It is extremely difficult to detect, especially if the percentage is small.
Solution 4. This is probably the most difficult problem to overcome and there is no easy solution for it. However, increasing the amount of test numbers and SMS tests themselves, as well as listening carefully to the feedback of your clients may increase your chances of eliminating such routes.
MNO CAUSED FAKE DLRS
Fake delivery receipts can be generated by certain MNOs in order to prevent delivery of unwanted traffic over grey ss7 routes from other mobile network operators. There are several variables which operators typically use in order to filter incoming traffic and generate fake delivery reports:
In order to overcome fake DLR issue caused by MNOs over ss7 connections, one should perform several variations of sender ID tests on mobile SMS test numbers in order to verify which senders are getting filtered.
Cause 1. Filtering based on Sender ID type. Most typically, operators may give fake DLRs on alpha sender IDs
Solution 1. Test with various sender ID types (alpha, local numeric, international numeric, short code) on a live test number and determine which sender IDs get filtered. Rewrite sender IDs into sender ID type which delivers or route traffic based on specific sender type criteria.
Cause 2. Filtering based on specific Sender IDs. Certain operators filter just some alpha or short-code sender IDs and allow others.
Solution 2. Test with various sender IDs on a live testing number will certainly help, however, if there is a significant amount of filtered sender IDs, it is highly suggested to rewrite all senders into a range of numeric long-codes.
Cause 3. Filtering based on throughput/bulk filters. Test message may deliver on a handset, however, when a batch of messages is sent, operator will give fake DLRs.
Solution 3. This can be difficult to verify by direct tests. However, you may want to duplicate your test message and send it as a batch to a range of numbers, which will include your test number as well. Including incorrect numbers may also help, positive delivery on such numbers may give an indication that the operator is giving fake DLRs.
- Try not to disclose your testing numbers to anyone, especially unreliable aggregators. Instead of a solution to your problem, eventually you will get even a bigger issue when your test numbers get whitelisted.
- Make your tests frequently, it will improve your chances of detecting an unreliable route.
- Try to send test messages with general content of your live traffic, it will make it less obvious that it is a test number.
- Never use “Test” or something similar as a sender ID of your message.
- And, most importantly, get rid of suppliers which frequently generate or sell you fake DLR routes.