Re: [stir] Making STIR SIP messages smaller

[Roman Shpount <[e-mail]>]

The average SIP INVITE size for the US PSTN is 1KB without Identity. This
was working great with UDP for most customers (do not confuse them with SIP
standard implementors). When these people start seeing an extra 2-3% of
call failures, they blame everybody but not their PSTN provider SBC vendor.
The only thing they care about and need is to keep their phones ringing and
calls completing.
_____________
Roman Shpount


On Tue, Apr 13, 2021 at 4:27 PM Christer Holmberg <
[e-mail]> wrote:

> Hi,
>
>
>
> SIP implementations need to support TCP, and they need to support long
> messages. If we wanted to make SIP more compact, there are tons of things
> we could do.
>
>
>
> And, if an implementations makes it or breaks it based on presence of the
> info parameter, that implementation is walking on very thin ice…
>
>
>
> Regards,
>
>
>
> Christer
>
>
>
> *From:* Chris Wendt <[e-mail]>
> *Sent:* tiistai 13. huhtikuuta 2021 23.14
> *To:* Roman Shpount <[e-mail]>
> *Cc:* Mary Barnes <[e-mail]>; Christer Holmberg <
> [e-mail]>; Alec Fenichel <
> [e-mail]>; Marc Petit-Huguenin <
> [e-mail]>; [e-mail] Mail List <[e-mail]>
> *Subject:* Re: [stir] Making STIR SIP messages smaller
>
>
>
> 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]> 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]>
> 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]> 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]> 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]
>
> [phone]
>
> TransNexus
>
>
>
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