Re: [stir] Making STIR SIP messages smaller

[Christer Holmberg <[e-mail]>]

Hi,

...

>You have other vendors, which are small VoIP operators using either open source or equipment from smaller companies. They do not participate in VoIP interops, do
>not follow the standards, and generally rely on their vendors to provide working equipment.

So, we shall modify the standards for people who don’t follow the standards?

>The fact that SIP over the reliable transports was badly designed in RFC3261 makes the problem worse. For some reason, RFC3261 assumed that sending INVITE over the reliable channel does not
>require retransmits and that you can send responses to INVITE over the address in VIA.

RFC 3261 does say that, for reliable transports, the response is normally sent on the connection on which the request was received.

   “For reliable transports, the response is normally sent on the
   connection on which the request was received.  Therefore, the client
   transport MUST be prepared to receive the response on the same
   connection used to send the request.”

I KNOW that there exist interoperability issues with TCP. But, if people implement TCP support wrong e.g., because they misunderstand the spec, shouldn’t we then instead clarify the spec?

Regards,

Christer




On Tue, Apr 13, 2021 at 4:14 PM Chris Wendt <[e-mail]<mailto:[e-mail]>> wrote:
Would be good to understand better why, i have not heard that feedback from the STIR/SHAKEN community lately or maybe folks have given up complaining :)  While there was much talk about it maybe 2-3 years ago, those conversations have been pretty quiet as of late. As far as i’m aware much of the equipment both commercial and open source and deployments have adapted and adjusted, but maybe there is parts of the eco-system that haven’t gotten there yet.

-Chris


On Apr 13, 2021, at 1:54 PM, Roman Shpount <[e-mail]<mailto:[e-mail]>> wrote:

Unfortunately, the message increase caused by the Identity header causes a call failure rate increase of at least a few percent. There is a substantial number of deployments affected by this and unlike things like History-Info, this feature is now required by law.
_____________
Roman Shpount


On Tue, Apr 13, 2021 at 1:50 PM Mary Barnes <[e-mail]<mailto:[e-mail]>> wrote:
Yeah - like nearly 20 years ago when we added headers like History-Info.   And, really if you want to use a text based protocol, you surely can't have small message sizes as a design priority.

On Tue, Apr 13, 2021 at 4:40 AM Christer Holmberg <christer.holmberg=[e-mail]<mailto:[e-mail]>> wrote:

>I agree that we need to figure out a way to make Identity headers smaller. As it stands right now, the Identity header with "shaken" PASSporT type adds around 600 bytes to an INVITE message.
>This makes typical SIP INVITE messages go from around 1K in size to 1.6K, which is bigger than the UDP MTU.

With or without Identity, didn’t that ship sail a long time ago? :)

Regards,

Christer



On Mon, Apr 12, 2021 at 5:39 PM Alec Fenichel <[e-mail]<mailto:[e-mail]>> wrote:
I guess what I am trying to say is that I think we should remove ppt from the examples because as you say, people tend to code to examples and smaller Identity headers would be ideal.

I don’t mean to hijack this thread, but I have been meaning to bring this up anyways and it is related. Is there a reason I’m just overlooking for requiring the “info” parameter when a full-form PASSporT is used? If not, can we make it optional? The reason I ask is that with OOB, the transit provider receives a PASSporT out-of-band and then needs to construct an Identity header. Because of the “info” parameter requirement, the transit provider must decode the PASSporT in order to determine the “info” parameter. This is the only reason that a transit provider needs to decode the PASSporT. This isn’t difficult so it doesn’t really matter, but I figured I’d ask about potentially making the “info” parameter optional. Also, it makes the Identity header smaller which is always a good thing.

Sincerely,

Alec Fenichel
Senior Software Architect
[e-mail]<mailto:[e-mail]>
[phone]
TransNexus

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