Agent L               Network               Agent R
   |(1) Offer            |                     |
   |------------------------------------------>|
   |(2) Answer           |                     |
   |<------------------------------------------|
   |(3) STUN Req.        |                     |
   |------------------------------------------>|
   |(4) STUN Res.        |                     |
   |<------------------------------------------|
   |(5) STUN Req.        |                     |
   |<------------------------------------------|
   |(6) STUN Res.        |                     |
   |-------------------->|                     |
   |                     |Lost                 |
   |(7) Offer            |                     |
   |------------------------------------------>|
   |(8) STUN Req.        |                     |
   |<------------------------------------------|
   |(9) STUN Res.        |                     |
   |------------------------------------------>|
   |(10) Answer          |                     |
   |<------------------------------------------|