Vpn feature for voipswitch Voip ($50 - $75)

[xbipin]

basically i use a softswitch on my dedicated server called voipswitch, now voip is blocked in the country i belong to so voipswitch provides a tunnel software, one end at server adn the other end at client, what this does is the SIP signalling port and RTP port is all reduced to the single port which is open on server
1805 or what ever we set

basically it takes those SIP and RTP packets from dialer or voip phone on the client side and encapsulates them in a simple UDP packet and sends to the single port on the server which then converts back to plain SIP and RTP and sends it to the softswitch.
to provide more details on this i can send u the client side tunnel software and i need the same feature in pfsense. it just has 4 parameters in the config, first the server ip, server port and then dummy sip signalling ip and port.
it just takes those packets and what i saw was removes the SIP header from it and renames it to SI_P so it becomes a plain UDP packet rather than SIP over UDP.
no registration etc required on client, it just takes packets, modifies header and send to server and takes from server and converts back to SIP and sent to voip phone, thats it, its basically a voip proxy, but helps in bypassing isp block.

plz quote amount for this feature and also send details on where i can send the client side tunnel software for u to review

[kapara]

What is this worth to you?  Try putting a dollar amount to it or you may not get many responses.

[xbipin]

i was just checking other ways and to make your work simpler, there is an open source project called openSBC along with it is open SIPstack and it uses a very basic form of encryption or lets say putting the data in the plain UDP packet and encryption is XOR and it bypasses the block.
actually i have a few ppl interested in using voip so i could give them the embedded PC with pfsense in it that would work as a standalone PC to encrypt voip or basically bypass the block.
Plz let me know how much u or some1 else would charge for such a thing as the code can be used from openSBC, the XOR encryption or something that sort and port it to pfsense as a plugin.
To my knowledge, porting the XOR method would be something like $50 or if u use the voipswitch way then $75 or $100.
im not sure what type of work is involved so u plz guide me how much should it be for.