Recommendations for simple IP2IP SIP VoIP provider?

Question

I am about to set up a mobile (3G & WiFi) closed/private company SIP VoIP implementation that meets the requirements listed below. Right now I'm pondering whether I'd go with a SIP server set up by myself at some hosting provider or should I find a third-party VoIP wholesaler, white label provider or VPS. In the latter case I'd prefer a solution with european-hosted media relays (at least) for latency considerations.

So, here are the requirements for the VoIP service:

- NO termination/PSTN or federation, only pure SIP over Internet on a single domain (closed private system much like Skype, without the Skypeout - with SIP softphones installed on mobile devices - CSipSimple on Android)
- mandatory TLS & ZRTP support
- enforce TLS and verify client certificate - no TLS or invalid certificate, no connection
- verify and enforce client user agent name - wrong UA name, no connection
- use of my own domain name
- DNS hosted by me or full access to DNS records
- full P2P + NAT traversal support
- media proxy/relay/TURN in Europe for small latency
- SIMPLE messaging
- IP & SIP flood prevention, dedicated IDS/IPS protection
- admin console for managing SIP accounts: add, modify, delete and temporarily disable users
- possibility to send messages to the connected devices from the admin console
- simple user database: no names or other personal data, only the numeric SIP ID and (hashed) login password
- remote API for managing SIP accounts and sending messages to devices, used by my own user administration software
- numeric user IDs: 1000-999999
- up to 2000 registered accounts
- NO need for billing, quotas, accounting etc.

Can anybody suggest a VoIP provider that meets the requirements above?

Answer 1

Since you don't want a PSTN interface, you're pretty much free to use any ISP with sufficient bandwidth and quality of service. I think you're going to find the QOS to be the tough part to guarantee.



At first glance it looks to me like any of the commonly available Asterisk programs (sometimes marketed at Trixbox) would handle your switching/ SIP/ authentication issue.



Your real headache is going to be quality of service. Unless you're planning to dump a ton of money into bandwidth and QOS equipment your best bet is going to be to find a rackspace provider who already has the necessary equipment in place... someone who is already handling industrial sized VOIP traffic.

Answer 2

I dont have much idea about voip and sip trunking though recently i came across a press release from a good company. i decided to recommend that to my customer and they seem to be pretty happy with their service. the prices were pretty reasonable as well and they had different solutions may be have a look at it.

Answer 3

many do free sip to sip, however Apple won't allow most IP phone apps as it undercuts the carriers.