

SIP from Twilio - sunsu
http://www.twilio.com/sip

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jxf
This is awesome news, and is really going to enable some powerful stuff (and
it'll be _cheap_! SIP/VoIP is far cheaper than using your minutes on a
traditional phone plan). For folks who haven't worked with Twilio before, one
of the slightly obnoxious parts is TwiML, their proprietary markup language
that describes how to make, route, and respond to telephony events. It's not
difficult to work with, but it's nonportable and irrelevant if you're not
using Twilio.

But now, by exposing the underlying SIP streams, Twilio is opening the doors
to a broader range of applications (commercial PBXs, enterprisey telephony
folks, etc.). Unfortunately, it looks like you still have to use TwiML to get
the job done, but all the custom stuff can be done on your side instead of
having to port that to TwiML.

~~~
pla3rhat3r
You're right. You still have to use a bit of TwiML to get the interop working
but man does it broaden the scope of what can be done. I can't wait to see
what people do with this.

~~~
RobSpectre
Really hope you'll both let us know what you build.

Share your enthusiasm - I think a much broader range of powerful business apps
are going to get made with this service.

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vaidik
Plivo ( <http://plivo.com> ) has been supporting SIP for a very long time.

~~~
loopdoend
My company moved to Plivo from Twilio. We've used them in production for 6
months or so now and they have saved us a ton of money. Their support is
great.

They have a gem and it's pretty simple to replace Twilio, there are some minor
changes in attribute names and such but all the functionality is there.

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josh2600
Can someone explain what the pricing is for? Is Twilio charging for the IP
delivery of SIP calls in addition to PSTN minutes?

In the interest of full disclosure, I am the marketing/community guy for
2600hz, the open-source cloud telecom company, but I am genuinely curious what
the per minute charge is for as it seems too low to include PSTN minutes.

~~~
RobSpectre
Great question Josh - always great to hear from you. Like all the voice
services Twilio delivers, SIP from Twilio is metered through per-minute usage
on each "leg." A leg refers to the connection of a voice call with respect to
Twilio's cloud. Your inference from the pricing is accurate - SIP legs and
PSTN legs are billed at different rates.

These descriptions can get a little unwieldy in prose, so consider this quick
example. Let's suppose you give me a ring at my Twilio number (718)989-1458
and I am at my desk with my SIP device. My per-minute Twilio usage for that
call would be the sum of you calling my Twilio number over PSTN (1 cent per
minute) and Twilio connecting that call to my SIP device (half cent per
minute). In summary:

\- You to my Twilio number (PSTN): $0.01 per min \- Twilio to my desk (SIP):
$0.005 per min \- Total: $0.015 per min

Does that help?

~~~
josh2600
Rob, as always, it's a pleasure :).

So if I call you and you use a SIP handset to answer it's $.015 per minute?
That accurately answers my question.

I still disagree with charging for pure IP transit, but that's more of a
marketing decision and I completely understand your reasons for doing so :).

I'd argue that the $.005 is unnecessary and Twilio would simply benefit
tremendously from the additional minutes volume from SIP apps, but you know
your business better than I do :).

~~~
RobSpectre
I can totally understand where you're coming from with that perspective. Like
Amazon, Heroku and other folks who are delivering valuable software through
utility pricing, we do often have to answer why we charge what we do on a per-
unit basis. This is particularly true of consumers of SIP products who have
spent their entire lives outlaying huge capital expenditures to buy gear in
order to get their business telephony apps running to connect their customers
and employees and then connecting using another provider with a relationship
governed by a different contract. Because the minutes used shows up on a
different bill than the stuff that uses the minutes, it is easy to keep the
two distant mentally.

For Twilio, it shows up in the same place. What you pay for is a simple (and
hopefully fun!) platform for changing the way your business communicates with
everything you need to do it - IVRs, conferences, queues, voicemail,
international, messaging and more. The way you pay is what we feel best aligns
your interests with ours - only what you use, only when you use it.

Like everyone else in startup tech, we hope we're delivering software at a
price that reflects the value our customers get from it. This feels right for
SIP From Twilio - hope you and others will continue to share your perspective
if it doesn't work for you.

Edit: fixed some typos.

~~~
josh2600
Rob, I've grown to love our public chats. You articulated the crux of the
issue for me and I see this as another element of the experience economy.

While I still disagree, I do understand the impetice to charge here as you are
certainly absorbing costs that would otherwise be born by the business.

There is definitely something to be said for the ease of integration and the
utilitarian nature of the Twilio tech. That value isn't free and I suppose
this is a good way to monetize twilio's efforts in this direction.

As always, I wish you guys the best and I really appreciate you taking the
time to clarify this topic :).

~~~
agwa
As a telephony enthusiast I enjoyed your exchange immensely. Thanks guys. It's
a great example of what makes HN special.

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lgbr
I've been waiting for this for a long time. Twilio Client (
<http://www.twilio.com/client> ) has been extremely glitchy and of course
lacks a lot of features that SIP clients can offer.

The best alternatives I can find are far more expensive. OnSIP runs about
$30/month, Line2 is about $10/month (and isn't even SIP), and RingCentral is
about $20/month. If I used 400 minutes per month here, I'd be paying $2 for
the minutes, and $1 for the phone number.

~~~
Terretta
I use Callcentric to give US phone numbers + SIP numbers to Android phones I
use as testing devices, and $0 beats $2 + $1:

<http://www.callcentric.com/dids/free_phone_number>

No affiliation, just the cheapest legit company offering a local phone number
+ SIP I've found that "just works" with Android Nexus phones as well as iOS
apps like Bria or Groundwire.

The free numbers are for NY, you can also try
<http://www.callcentric.com/dids/phone_number_sale> to see if there's a
$2.95/month number local to you. Not that it matters for SIP.

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JSadowski
Unfortunately, unless I'm missing something, Twilio still appears unable to
handle inbound sip

~~~
RobSpectre
That is accurate - SIP From Twilio is connect from Twilio to your SIP gear. We
do not yet support SIP from your gear to Twilio.

After much consideration and talking with our customers, we decided to release
our SIP features as it met our standard of quality rather than hold up release
on bidirectional functionality.

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sunsu
I've been using Twilio's SIP Support in production at Better Voicemail for a
few months now. The implementation is rock solid and adds a lot of value to
Twilio's offering especially when it comes to integrating with existing
business systems. Also, supposedly outbound calls through SIP endpoints is
coming "in a couple of quarters".

~~~
RobSpectre
Awesome! _hifives_

Glad to hear the experience is going well. Hope you'll keep us updated on how
it's working out for you.

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650REDHAIR
I love Twilio.

Danielle got me hooked back in '09 and I've been a big fan since, but I'm
really curious as to why it took so long for SIP support?

Was it not requested enough or were the engineering challenges just too great
years ago?

~~~
RobSpectre
We love you! _hifives_

Timing is a great question and there a jillion factors involved - both our
customers and the market have changed considerably in just the few years we've
been around.

I'm not sure that engineering challenge is often a primary blocker on picking
the products we bring to market - most everything we work on ends up being
pretty tough. In the case of SIP From Twilio, I think it was more driven by
the market trend of moving critical applications from on-premise hardware to
the cloud.

We still have a lot of work to do to prove doing such makes as much sense in
the phone closet as the server room. Complementing that effort with SIP
connectivity now felt right.

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bencevans
If only Vodafone/Mobile phone companies would provide SIP support so I can use
my credit and number.

~~~
josh2600
They offer this sort of support, it's just expensive.

There's only one carrier that's remotely wholesale friendly in the US and
that's sprint, but they'll give you full SIP interop. As far as using your
credit or your phone number, I can't see the carrier relinquishing that
stranglehold.

Your credit is your money and your number is your identity. Those are the two
most valuable bargaining chips in the mobile carriers arsenal. The real
disruption would be in federating identity and finance on a mobile platform,
but I'm not holding my breath. While there are projects like this today, it's
unlikely that any of them will reach the scale where significant network
effects can take place.

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knodi
Any plans on SMPP support for SMS traffic?

~~~
RobSpectre
Don't have anything to report here, though I would love to hear how you would
use such a feature.

Can you shoot me what you think to rob [at] twilio?

