Text messages lost over the pond

[ajay11]

WHen you look at the FAQs of companies like Twilio, TextMagic, or FastSMS you quickly realize they all warn you. If you need to send text messages (and receive answers) to a subscriber in the U.S. you better use a US mobile phone number (or a virtual mobile number). And in Europe you better use a European number. "We cannot guaranty" ... they say, that text messages aren't lost when they cross the big pond. Sometimes sending works, responding doesn't. Sometimes messages get truncated or filtered.

It all confirms my own experience, that sending a simple SMS from my phone to the other side of the pond, messages often get lost. Incompatibilities between GSM and non-GSM networks ? I can't believe it.
Anybody to know the "technical" reason for these limitaitons ?

 

[DelJo63]

I beleive that all of Europe is GSM and CDMA is rare.

I would have to look under the covers to see if SMS is using UDP or TCP for connections -- my guess would be UDP and that would explain the unreliable messaging.

 

[DelJo63]

[update] Messages are sent to a short message service center (SMSC), which provides a "store and forward" mechanism. It attempts to send messages to the SMSC's recipients. Some SMSCs also provide a "forward and forget" option where transmission is tried only once. Message delivery is "best effort", so there are no guarantees that a message will actually be delivered to its recipient, but delay or complete loss of a message is uncommon, typically affecting less than 5 percent of messages.

SMS is implemented on TCP/IP so theoretically is should be a reliable delivery

 

[DelJo63]

My experience has been iMessage from California to Rome, Italy have been reliable.