Click here to Skip to main content
15,436,765 members
Articles / Desktop Programming / Win32
Posted 6 Feb 2008


26 bookmarked

Stunner: A STUN Library and Client

Rate me:
Please Sign up or sign in to vote.
3.58/5 (8 votes)
6 Feb 2008CPOL2 min read
Stunner is a simple STUN library on top of which a STUN client is built.
Image 1


Stunner is a simple STUN library and client built on top of it in C++, which helps to determine the NAT type, STUN mapped IP and port. I did this as an exercise for myself and it's thus based upon RFC 3489. If there is enough interest, then I might work on support for the latest STUN draft. It doesn't support the shared secret requests and responses as described in RFC 3489. The main reason for this is that I don't see any STUN server, which requires or supports the shared secret requests. Again, if there is enough interest then I will add this as well. All the basic classes for parsing and sending STUN requests and responses are there, thus it should be fairly easy to build a STUN server based on the library. The library is single threaded and uses the select I/O model for WinSock functions.


If you are not sure what STUN is, then please refer to RFC 3489.

Using the STUN Client

To determine the NAT type and STUN mapped IP, you can call the following functions:

CStunClientHelper clientHelper (""); 
NAT_TYPE Nat = clientHelper.GetNatType (); 
clientHelper.GetStunMappedAddress (&addr); 

The GetNatType function performs the tests as described in RFC 3489 and GetStunMappedAddress function gets you the public IP by sending a binding request.

Points of Interest

In case we fail to get a response for a request then we don't retry eight times as specified in RFC 3489, instead we just try three times. Moreover, we don't wait for ten seconds of receiving a response and check if all further responses to the request have the same IP and perform other validations as described in RFC 3489. The reason for this is to make the STUN client return back in proper time so that the application could use the results, however if you want the behavior described in RFC 3489 then add STRICT_IMPLEMENTATION to the preprocessor definitions. And for logging to a file, add LOG_TO_FILE to the preprocessor definitions.


  • 7th February, 2008: Released first version


This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Written By
United States United States
This member has not yet provided a Biography. Assume it's interesting and varied, and probably something to do with programming.

Comments and Discussions

QuestionStunClientHelper is Incompatible with Multiple Interfaces Pin
Member 1501134611-Feb-21 11:57
MemberMember 1501134611-Feb-21 11:57 
Questionfunction CStunBindingResponseMessage::GetChangedAddress() does not have a null check Pin
kimfeng8-Oct-16 23:30
Memberkimfeng8-Oct-16 23:30 
Questionsame in XP Pin
Peter Eugene Coleman31-Mar-14 20:56
MemberPeter Eugene Coleman31-Mar-14 20:56 
QuestionCompiles but doesn't run Pin
Peter Eugene Coleman31-Mar-14 20:55
MemberPeter Eugene Coleman31-Mar-14 20:55 
lok.vikram9-Aug-10 22:46
Memberlok.vikram9-Aug-10 22:46 
Generalhi Pin
Salim_Imp11-Feb-08 23:47
MemberSalim_Imp11-Feb-08 23:47 
GeneralRe: hi Pin
Hitesh Sharma12-Feb-08 0:58
MemberHitesh Sharma12-Feb-08 0:58 
GeneralRe: hi Pin
hawkgao012916-Feb-08 18:32
Memberhawkgao012916-Feb-08 18:32 
GeneralRe: hi Pin
somi123426-Nov-08 9:11
Membersomi123426-Nov-08 9:11 
GeneralRe: hi Pin
hawkgao012926-Nov-08 15:12
Memberhawkgao012926-Nov-08 15:12 

General General    News News    Suggestion Suggestion    Question Question    Bug Bug    Answer Answer    Joke Joke    Praise Praise    Rant Rant    Admin Admin   

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.