Looking at getting a SIP provider for international calls. I am somewhat impeded by not knowing anything about SIP and RTP, although I have a SIP client on this phone.
An overview, as I understand it: SIP is the standard call setup protocol for VoIP; RTP is the protocol used for the actual data. The company that hooks up VoIP calls to the PSTN (public switched telephone network) is called a “SIP provider” or “ITSP” (“internet telephony service provider”). Much of the SIP business currently comes from companies who want to hook up their PBXes to the PSTN. A “DID” (“Direct Inward Dial [number]”) is a non-toll-free incoming phone number. An “ATA” is a SIP-speaking device you can plug an analog phone into.
SIP phones can speak directly to each other over the internet as well.
Voip.ms seems to be one of the default choices, and I think it would cost US$1.50 per month for E911 service (though maybe that’s optional?), US$0.85 to US$1.25 per month for an incoming phone number (plus US$0.40 to set it up), and about US$0.01 per minute both inbound and outbound, including to “toll-free” numbers. You need a minimum of US$15 prepaid to do incoming or outgoing calls, but you can sign up for an account and use their voice call test thing without paying. They offer a broad spectrum of features.
SIPStation offers service at US$24.99 a month for a monthly plan, plus (?) US$1 per month plus US$0.024 per minute.
Vitelity apparently no longer allows new customers to sign up for VoIP since merging with Voyant in February 2018; they’re 100% focused on the VoIP VAR market now.
The FreeSWITCH Wiki page has a lot of stuff about working around problems, which I take to mean that they were very popular, not that they had a lot of problems.
Google Voice apparently does support SIP but will cut you off if they detect you’re calling 1-800 numbers from a non-US IP address. Added to that is the constant menace that they may link your phone number to your Google account, so a problem on one means losing the other. Not an option I’d ever consider.
Flowroute charges US$1 for setup and US$1.25 per month, plus the Federal Universal Service Fund charge (of some unknown amount?) plus US$0.012 per minute inbound and US$0.0098 per minute outbound. They default to business accounts but also offer personal accounts. They have technical details.
The FreeSWITCH Wiki page just offers some XML from 2013.
Vonage mostly doesn’t offer SIP, though the FreeSWITCH Wiki page explains that secretly they do through resellers. Not an option.
Bandwidth.com focuses on “the biggest brands” and has a free trial.
The FreeSWITCH Wiki page explains how to make it work as of 2011.
The above is partly collated from the below.
Freeswitch.org has a list that is far too long to consider. But the page for voip.ms, aka Swiftvox (last updated 2014) shares chunks of XML to use to configure, I guess, FreeSWITCH, to work properly with voip.ms. Also implies voip.ms defaults to being configured for “ata device, ip phone or soft phone”, which is what I have, of course.
A year ago, jhalstead was looking at “FlowRoute, Vonage, voip.ms, nextiva, Sipstation”. Someone else in the thread suggested Telnyx; another person seconded the FlowRoute recommendation, and cyberchaplain said, “I’ve personally used Bandwidth, Level3, Flowroute, callwithus and voip.ms and can’t complain about any of them really.” Others mentioned Vitelity, Touchtone Communications, and Spectrum/TWC, and a Nextiva employee tried to persuade them to switch to hosted. This suggests that, at the time, FlowRoute and voip.ms were the popular options. But this thread is mostly oriented toward companies with PBXes.
An ad for Vitelity used SIPStation as their comparison competitor. The ad seems to be directed at small businesses like a “hardware store or restaurant” who want to get phone service for on the order of US$3.99 a month (vs. US$100 with SIPStation), but also those who want to “scale up to hundreds of trunks”. It also mentions SIPStation’s ability to spoof caller ID as a benefit, allowing you to use SIPStation for outgoing calls while receiving your incoming calls on a different number. The main point of the post seems to be that it’s good to pay by the minute rather than by the phone line, and an addendum notes that eventually SIPStation switched to charging by the minute too. Another addendum notes that Vitelity is now Voyant Communications and “has halted new registrations for the time being”.
An ad for SIPStation from 2017 touts the benefits of their pricing; its example company is paying US$499 a month for two locations with 10 lines, but by using SIPStation’s “trunk groups” they can switch to just 15 lines an pay only US$374.25 a month. Pretty cheap if you're a company with multiple offices and dozens of employees, I guess.
voip.ms publishes their pricing information as follows:
Outgoing Calls, USA Rates
- Premium Route: $0.0100 (1¢) per minute
- Toll-Free Numbers Value Route: Free
- Toll-Free Numbers Premium Route: $0.0106 (1.06¢) per minute
- e411: $0.99 per call. Must be activated by customer in settings
Incoming calls, USA / Canada DID Per Minute Pricing
- Monthly Fee:
USA: $0.85 to $1.25
Canada: $0.85 to $1.70- Per minute inbound:
$0.009 to $0.0125- One time setup Fee: $0.40
- Billing Increment: 6 seconds
- Channels: 25
- Intended Use: Any
Extras Features
- E911/911 $1.50 per month
Seven months ago Blade_Fox moved from Vonage to voip.ms, though they didn’t explain why, and wanted help getting SMS working. Mizzlezz, in the comments, is using Bandwidth.com.
Last year johndrwhosmith was looking for recommendations for a “hosted/cloud PBX”, saying they were thinking of Nextiva, and slayter commented:
do not use voip.ms unless you are experienced in VOIP or intending for residential usage. They have failed to register as a telecom in Canada and could even be shut down tomorrow with nothing to say about it.
Maybe I’m being too blasé but I don’t see that as a big problem.
Four years ago pseud_o_nym was going to “port” their phone
number from Comcast to ring.to, and RocketTech99 recommended looking
at voip.ms (though it was “not [their] favorite provider”, they “have
a very low entrance cost”.)
Two years ago, jrdbm, a reseller of Bandwidth.com’s VoIP service, asked for help with some porting problems, and got recommended FlowRoute.
This thread from last year explains when Google Voice cuts you off. People are also recommending voip.ms and Callcentric in there, but I think the Callcentric recommendation is from someone who works at Callcentric.
Other pages to read: a b c d e.