A method of providing access of a mobile terminal to an IP network via a plurality of routers having security gateways, the method including: - establishing a security association, SA, between said mobile terminal and a first security gateway (SGW HOME) of a first router (IAR HOME) in said plurality, - associating an IP address (IP MS) to said mobile terminal and providing access of said mobile terminal having associated said IP address to said IP network via said first router (IAR HOME), wherein data exchanged between said mobile terminal having associated said IP address and said first router (IAR HOME) are encapsulated by using said security association, SA, - making said security association, SA, available to at least one second router (IAR VISITED) in said plurality, said at least one second router (IAR VISITED) having a second security gateway (SGW VISITED), - providing access of said mobile terminal having associated said IP address to said IP network via said at least one second router (IAR VISITED), wherein data exchanged between said mobile terminal having associated said IP address and said at least one second router (IAR VISITED) are encapsulated by using said security association, SA, made available to said at least one second router (IAR VISITED), - establishing said security association, SA, between said mobile terminal and said first security gateway (SGW HOME) includes assigning a Security Parameter Index, SPI, to said security association, SA, said Security Parameter Index, SPI, identifying univocally said first security gateway (SGW HOME) and said security association, SA, and - making said security association, SA, available to said at least one second router (IAR VISITED) includes: - receiving at said second security gateway (SGW VISITED) a data packet from said mobile terminal, said data packet comprising said Security Parameter Index, SPI, whereby said second security gateway (SGW VISITED) identifies said first security gateway (SGW HOME) based on said Security Parameter Index, SPI, and - requesting and obtaining said security association, SA, at said second security gateway (SGW VISITED) from said first security gateway (SGW HOME), thereby enabling said at least one second router (IAR VISITED) to have access to said security association, SA, characterized by: - assigning an anycast IP address, IPAny_cast, to said security gateways (SGWHOME. SGWVISITED) of said plurality of routers, and - establishing an IP connection between said mobile terminal and one security gateway (SGWHOME- SGWVISITED) out of said security gateways (SGWHOME, SGWVISITED) by means of said anycast IP address, IPAny_cast. - establishing a security association, SA, between said mobile terminal and a first security gateway (SGW HOME) of a first router (IAR HOME) in said plurality, - associating an IP address (IP MS) to said mobile terminal and providing access of said mobile terminal having associated said IP address to said IP network via said first router (IAR HOME), wherein data exchanged between said mobile terminal having associated said IP address and said first router (IAR HOME) are encapsulated by using said security association, SA, - making said security association, SA, available to at least one second router (IAR VISITED) in said plurality, said at least one second router (IAR VISITED) having a second security gateway (SGW VISITED), - providing access of said mobile terminal having associated said IP address to said IP network via said at least one second router (IAR VISITED), wherein data exchanged between said mobile terminal having associated said IP address and said at least one second router (IAR VISITED) are encapsulated by using said security association, SA, made available to said at least one second router (IAR VISITED), - establishing said security association, SA, between said mobile terminal and said first security gateway (SGW HOME) includes assigning a Security Parameter Index, SPI, to said security association, SA, said Security Parameter Index, SPI, identifying univocally said first security gateway (SGW HOME) and said security association, SA, and - making said security association, SA, available to said at least one second router (IAR VISITED) includes: - receiving at said second security gateway (SGW VISITED) a data packet from said mobile terminal, said data packet comprising said Security Parameter Index, SPI, whereby said second security gateway (SGW VISITED) identifies said first security gateway (SGW HOME) based on said Security Parameter Index, SPI, and - requesting and obtaining said security association, SA, at said second security gateway (SGW VISITED) from said first security gateway (SGW HOME), - receiving at said second security gateway (SGW VISITED) a data packet from said mobile terminal, said data packet comprising said Security Parameter Index, SPI, whereby said second security gateway (SGW VISITED) identifies said first security gateway (SGW HOME) based on said Security Parameter Index, SPI, and - requesting and obtaining said security association, SA, at said second security gateway (SGW VISITED) from said first security gateway (SGW HOME), - assigning an anycast IP address, IPAny_cast, to said security gateways (SGWHOME. SGWVISITED) of said plurality of routers, and - establishing an IP connection between said mobile terminal and one security gateway (SGWHOME- SGWVISITED) out of said security gateways (SGWHOME, SGWVISITED) by means of said anycast IP address, IPAny_cast.