arges. The new software release will have the latest improvements incorporated into the base software as well as new optional software functions and features being offered by the vendor. The vendor presents its feature release roadmap to the operator well in advance, in order to provide relevant information about the content and delivery of the coming releases. The new software release process will include production, testing and provision of a software delivery containing storage media and required EPROMs of the new software release as well as production and delivery of one documentation set. If the operator agrees to accept the new software release, then the vendor arranges for its installation in the operator's testbed. Once satisfied with the performance, if the software installation is to be extended to other parts of the network, it is done like a software roll-out process followed by a testing schedule and a field acceptance procedure. If certain flaws or bugs are found then the vendor has to agree to bring about a change delivery with the required corrections. If the operator does not agree to accept the software on the basis of the results obtained from field-testing activities, but still goes ahead by putting it into commercial use, then automatically the software is deemed to be accepted. Fault Management Fault management encompasses the vendor's responsibility to perform initial fault detection procedures and subsequently issue change notes and change deliveries. The operator also has to carry out regular software fault detection procedures at various sites and identify the problem and notify the vendor by filling a failure report. If required by the vendor, the operator will have to provide additional information, like logs, symptoms, alarms, counters, etc. If the operator fails to respond to the request for additional information within a specific period of time then the vendor can close the failure case. Software corrections are prepared based on failure reports received from the operator and other