What is the IP address of the web server in Java Card 3.0 connected version?

Question

When we run a web server in a java card 3.0 compatible card, how can we request that server or rather at which IP address do we request that server. Further more can an android app request and get a response from the server if so how can we do it ?

Answer 1

Obviously if it isn't directly connected to a network it cannot obtain an IP address by itself (it would not be much use if it could). If there is an IP address assigned to it it must be on the host machine, routing the packets to the smart card.

Or, as the standard states in the JCRE spec of the 3.0.1 connected edition:

A Java Card Platform implementation is not required to support the TCP/IP or UDP/IP on card. Connections over HTTP, HTTPS, and TLS protocols and datagrams over the UDP protocol MAY be supported over IP, as well as non-IP protocols, by using a gateway on the terminal or hosting device. The TLS protocol MUST be supported on card.

But also:

Applications MUST NOT be required to know that a non-IP protocol is being used.

So basically the host will receive a TCP/IP stream, and convert it into packets towards the card.