Free SIP Outbound Proxy Service

July 2012 Update: SIP Outbound Proxy Service is NOT Free anymore.


What's this?

A Commercial SIP Outbound Proxy Service, that bridge SIP signal messages between SIP client and SIP proxy server through UDP port other than the standard 5060, by this to bypass the ISP's blocking on broadband phone service.

How it works?

SIP outbound proxy is the part of the SIP protocol standard defined in RFC 3261

The outbound proxy server's hostname is, there have up to 12 opened UDP port numbers for use, just pick up one port which works in your ISP's scenario.

Here is the list of all running UDP ports for this service:

How to setup the SIP client?

You don't need touch any existing settings your broadband phone service required, but just touch the outbound proxy settings in your SIP devices.
When you enabled Outbound Proxy, mostly you don't need enable STUN support in your SIP client any more.

  • Linksys/Sipura boxes

Use Outbound Proxy: yes
Outbound Proxy:
Use OB Proxy In Dialog: yes

  • Grandstream boxes

Outbound Proxy:

  • X-Lite Softphone

Send outbound via: proxy Address

Have questions or suggestions?

Send email to info at sippp dot com (change 'at' to @ and change 'dot' to . )


  • Jan 2007 - FreeSPS service released to public for FREE SIP outbound server
  • Aug 2009 - Upgraded to FREE.SIPOUT.COM with best data center and dedicated bandwidth
  • Aug 2010 - Upgraded to P.SIPPP.COM platform with full technical support and new level of system reliability and capacity
  • Jul 2012 - This service is NOT free anymore!

Created by: forvoip, Last modification: Wed 25 of Jul, 2012 (03:56 UTC) by pinazo
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