4 ms·

Great post. I used to work with SMS for a living, and still remember the first time I visited a customer's data center and watched one of their engineers send

Great post. I used to work with SMS for a living, and still remember the first time I visited a customer's data center and watched one of their engineers send an SMS... by telnetting directly into the SMSC and punching out a command in raw EMI: https://en.wikipedia.org/wiki/EMI_(protocol) https://en.wikipedia.org/wiki/EMI_(protocol) And an old blog post of mine on why MMS failed but still managed to delay actual mobile internet by 10 years: https://gyrovague.com/2014/06/27/how-sms-set-back-the-mobile-internet-by-ten-years/ https://gyrovague.com/2014/06/27/how-sms-set-back-the-mobile...

voltagex_ 8y ago
I wonder if there's a good technical writeup on MMS. It seems to be "just another" IP based thing, but I've never really investigated it.
- jpatokal 8y ago
  Wikipedia goes into this in some detail, but it really is pretty much the canonical example of a protocol designed by committee. https://en.wikipedia.org/wiki/Multimedia_Messaging_Service https://en.wikipedia.org/wiki/Multimedia_Messaging_Service Here's the technical spec, which manages to combine the single bit level detail of old school telco with the enterprisey goodness of SOAP. http://www.qtc.jp/3GPP/Specs/23140-6g0.pdf http://www.qtc.jp/3GPP/Specs/23140-6g0.pdf For example, this is how you say "OK" in MM7: HTTP/1.1 200 OK Content-Type: text/xml; charset="utf-8" Content-Length: nnnn <?xml version="1.0" ?> <env:Envelope xmlns:env="http://schemas.xmlsoap.org/soap/envelope/"> <env:Header> <mm7:TransactionID xmlns:mm7="http://www.3gpp.org/ftp/Specs/archive/23_series/23.140/schema/REL-5-MM7-1-3" env:mustUnderstand="1"> vas00001-sub</mm7:TransactionID> </env:Header> <env:Body> <SubmitRsp xmlns="http://www.3gpp.org/ftp/Specs/archive/23_series/23.140/schema/REL-5-MM7-1-3"> <MM7Version>5.6.0</MM7Version><Status> <StatusCode>1000</StatusCode> <StatusText>Success</StatusText></Status> <MessageID>041502073667</MessageID> </SubmitRsp> </env:Body></env:Envelope>
  - maaarghk 8y ago
    jesus christ. No wonder I could never send the things! Your blog post above was also a good read. Thanks.

voltagex_ 8y ago

I wonder if there's a good technical writeup on MMS. It seems to be "just another" IP based thing, but I've never really investigated it.

jpatokal 8y ago
Wikipedia goes into this in some detail, but it really is pretty much the canonical example of a protocol designed by committee. https://en.wikipedia.org/wiki/Multimedia_Messaging_Service https://en.wikipedia.org/wiki/Multimedia_Messaging_Service Here's the technical spec, which manages to combine the single bit level detail of old school telco with the enterprisey goodness of SOAP. http://www.qtc.jp/3GPP/Specs/23140-6g0.pdf http://www.qtc.jp/3GPP/Specs/23140-6g0.pdf For example, this is how you say "OK" in MM7: HTTP/1.1 200 OK Content-Type: text/xml; charset="utf-8" Content-Length: nnnn <?xml version="1.0" ?> <env:Envelope xmlns:env="http://schemas.xmlsoap.org/soap/envelope/"> <env:Header> <mm7:TransactionID xmlns:mm7="http://www.3gpp.org/ftp/Specs/archive/23_series/23.140/schema/REL-5-MM7-1-3" env:mustUnderstand="1"> vas00001-sub</mm7:TransactionID> </env:Header> <env:Body> <SubmitRsp xmlns="http://www.3gpp.org/ftp/Specs/archive/23_series/23.140/schema/REL-5-MM7-1-3"> <MM7Version>5.6.0</MM7Version><Status> <StatusCode>1000</StatusCode> <StatusText>Success</StatusText></Status> <MessageID>041502073667</MessageID> </SubmitRsp> </env:Body></env:Envelope>
- maaarghk 8y ago
  jesus christ. No wonder I could never send the things! Your blog post above was also a good read. Thanks.