5 ms·
Signalling System No 7
- digi_owl 8y ago> In February 2016, 30% of the network of the largest mobile operator in Norway, Telenor, became unstable due to "Unusual SS7 signaling from another European operator". Supposedly this happened because the other telco had hired a pentester...
- myrandomcomment 8y agoBuilt before the idea of bad actors was a thing..
- nathanaldensr 8y agoIt's interesting how one can separate protocols into those two buckets: 100% trusting and 100% suspicious. Edit: Maybe 100% is too rigid, but you get the idea. ;)
- wolrah 8y agoMost certainly not. One of the purposes of the move to out-of-band signaling was to stop the various "box" attacks on the tone-based in-band signaling used previously. They were very aware of bad actors, they just assumed that their private signaling network would remain private and thus any bad actors with access would be easy to identify and deal with. They never imagined the situation we have today with tens of thousands of telephone service providers and even large customers of those having direct access to the signaling network.
- myrandomcomment 8y agoLet me try again. Built before bad actors that were the state, or someone smarter then hackers on the outside, were a thing. SS7 once you are on net with it is pretty wide open.
- kikoreis 8y agoSadly heralding the end to an incredible run of blue boxing..
- kokey 8y agoFortunately it took a while for ss7 to be adopted on all international trunks.
- deleted 8y ago[deleted]
- kpil 8y agoWhile a bit unergonomic to work with, the .7 protocols uses ASN.1 for defining and describing a lot of the protocols and messages. ASN.1 have some nice ideas that the developer community has failed to grok, reverting back to simpler ideas that are more immediately rewarding, such as hand coding a lot of code that blasts away text based messages that may or may not be understandable to the recipients because, hey it works on my machine. The core idea is that there is a language that defines the abstract message content, and there can be several encoders - binary, text, compact binary, depening on needs and computing and bandwidth requirements. There are also some support for defining the criticality of any extensions to a protocol, to inform recipients if the can disregard an additional part it does not understand or if it's critical. This is not an afterthough as json schema, but the core idea.
- sebcat 8y agoASN.1 JER (JSON Encoding Rules) exists, for anyone who wants it.
- cesarb 8y agoPart of the issue might be a variant of FUTON bias (https://en.wikipedia.org/wiki/FUTON_bias https://en.wikipedia.org/wiki/FUTON_bias): can I easily get the official text of the ASN.1 standard, without having to register somewhere and/or pay hundreds of Euros?
- otterlicious 8y agoYes, the ASN.1 standards are freely available: https://www.itu.int/en/ITU-T/asn1/Pages/introduction.aspx https://www.itu.int/en/ITU-T/asn1/Pages/introduction.aspx
- kpil 8y agoI think it specifically is not used because it's a more complex idea that requires a lot of initial effort and mental work until the benefits are apparent. I guess it's just like most other "actually better than x" languages and standards out there. In this case it's also not the nicest language to read and it's a bit dated. It would be nice with an ASN.2 though...