Retaining capability of handling original type messages in an upgraded computer system

Interface device for routing of messages between an external network and an internal network including:

• a first port connectable to the external network for transmission of messages according to a first addressing protocol and having a first address according to the first protocol, where transmitted messages comprise messages including embedded messages according to a second addressing protocol and original messages according to the first protocol,
• a second port connectable to a first part of the internal network and a control unit arranged to:
• assign the second port as a port to be used for all messages not including embedded messages,
• assign a second address to the second port, which is closely related to the address of the first port, and
• inform the first part of the internal network about the second port and its address, such that original messages according to the first protocol can be transferred between the internal network and the external network.

An internal network for communicating with an external network comprising:

• a first part and
• an interface device connectable between the first part and the external network, said interface device comprising:
• a first port connectable to the external network for reception of messages sent according to the first protocol and having a first address according to a first addressing protocol, where received messages comprise messages including embedded messages according to a second addressing protocol and original messages according to the first protocol,
• a second port connected to the first part of the internal network, and
• a control unit arranged to:
• assign the second port as a port to be used for all messages not including embedded messages,
• assign a second address to the second port, which is closely related to the address of the first port, and
• inform the first part of the internal network about the second port and its address, such that original messages according to the first protocol can be transferred between the internal network and the external network.

Computer program product comprising a computer readable medium to be used on a computer connectable between an internal and an external network and having a first address according to a first addressing protocol to be used on a first port connectable to the external network for transmission of messages according to the first protocol, where transmitted messages comprise messages including embedded messages according to a second addressing protocol and original messages according to the first protocol, said computer readable medium having thereon:

• computer program code means, to make the computer execute, when said program is loaded in the computer:
• assigning a second port connectable to a first part of the internal network as a port to be used for messages not including embedded messages,
• assigning a second address to the second port, which is closely related to the address of the first port, and
• informing the first part of the internal network about the second port and its address, such that original messages according to the first protocol can be transferred between the internal network and the external network.

Computer program element to be used on a computer connectable between an internal and an external network and having a first address according to a first addressing protocol to be used on a first port connectable to the external network for transmission of messages according to the first protocol, where transmitted messages comprise messages including embedded messages according to a second addressing protocol and original messages according to the first protocol, said computer program element comprising:

• computer program code means, to make the computer execute, when said program is loaded in the computer:
• assigning a second port connectable to a first part of the internal network as a port to be used for messages not including embedded messages,
• assigning a second address to the second port, which is closely related to the address of the first port, and
• informing the first part of the internal network about the second port and its address, such that original messages according to the first protocol can be transferred between the internal network and the external network.