US 7,321,598 B2
Method and apparatus for connecting IPv6 devices through an IPv4 network using a tunneling protocol
Marc Blanchet, St-Augustin (Canada); and Florent Parent, Cap-Rouge (Canada)
Assigned to Hexago Inc., Montreal, Quebec (Canada)
Filed on Jul. 16, 2002, as Appl. No. 10/195,396.
Prior Publication US 2004/0013130 A1, Jan. 22, 2004
Int. Cl. H04J 3/16 (2006.01); H04J 3/22 (2006.01)
U.S. Cl. 370—466  [370/389] 30 Claims
OG exemplary drawing
 
1. A method for connecting IPv6 devices through an IPv4 network to an IPv6 node in an IPv6 network using a tunnel setup protocol, comprising steps of:
using Transfer Control Protocol (TCP) messaging to establish a control channel between a tunnel client in the IPv4 network and a tunnel broker server in the IPv4 network; and
at the tunnel client:
sending to the tunnel broker server, via the control channel, a request to establish an IPv6-in-IPv4 tunnel through the IPv4 network, the request including tunnel configuration parameters desired by the tunnel client; and
receiving from the tunnel broker server, via the control channel, any one of: a first acceptance of the request with a specification of information respecting the tunnel configuration parameters; a second acceptance of the request with a specification of at least one alternate parameter for the tunnel configuration; and, a refusal of the request;
wherein:
if either acceptance of the request is received from the tunnel broker server, the tunnel client periodically sends a keep-alive message to the tunnel broker server to maintain the tunnel setup protocol session with the tunnel broker server; and
if a refusal of the request is received from the tunnel broker server, the tunnel client further receives from the tunnel broker server, via the control channel, a list of alternate tunnel broker servers which may be used by the tunnel client.