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On 6/19/2018 12:24 PM, Alex Balashov wrote:<br>
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<pre wrap="">Abandoning SIP over UDP is a major topic for me these days. Once upon
a time SBC's were a great place to prune packets to limbo under the
1500 byte MTU bar, but as we all know this is a losing battle with the
bloating of SDP's and the supported header, and can cause random
breakage. Furthermore with the internet at large becoming increasingly
hostile towards UDP as a transport due to the massive DDOS
possibilities many UDP protocols offer, the sip over udp client space
is becoming increasingly difficult. Moving access-side to TCP offers
literally nothing but upside, with one exception, failover, as you
well identified. Of course an open-source SBC in software carried with
it the possibility for automation and orchestration, and if you go
TCP, then there's literally no excuse to not encrypt everywhere and go
TLS with LetsEncrypt. TLS signaling also carries the benefit of
carving through ALG's and anti-competitive ISP practices.
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<pre wrap="">I don't think most of the ITSP industry has moved to that insight yet,
although anecdotally, it appears that the metastasis of increasingly
tenacious ALGs is creating a NAT support crisis.
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Worth noting here that i think its going to be regulatory issues
that force this first on the peering side with SHAKEN/STIR (somewhat
forced acronyms) advocating the cryptographic signing of invites at
the hop-on point. This is pretty much guarenteed to break most
current peering relationships and force carriers into at minimum TCP
to support the signature payloads. <br>
<br>
Getting a handle on moving to TCP/TLS now will simply make you more
effective when the inevitable happens.<br>
<br>
FWIW I fully support signing of invites and identity headers, but
the proposals in SHAKEN/STIR i think are barking up an unsustainable
bureaucracy tree that makes me want to watch Brazil. <br>
<br>
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