The present invention relates to the testing of functional or IP cores forming part of a system on chip, SoC. The invention is implemented using a testing means and a communication means to test at least one functional or IP core. The testing means comprises a wrapper in which the core is embedded, this wrapper implements preferably the IEEE P1500 standard architecture but can also implement other standard architectures. The testing means can be extended to a Simple Network Management Protocol, SNMP, the widely adopted TCP/IP management protocol. The communication means comprises a test bus connected to the communication network. The proxy agent can implement the SNMP protocol, among others.