摘要:
In a data distribution system, data is divided into a number of application data units. A sequence of keys is generated systematically, and a different key is used to encrypt each data unit at the source. At the receivers, corresponding keys are generated and used to decrypt the data units to gain access to the data. The constructions used to generate the keys are such that an intrinsically limited subset of the entire sequence of keys is made available to the user by communicating a selected combination of one or more seed values.
摘要:
Methods and an associated traffic management module and system are disclosed for monitoring, at a traffic management module (26) within a data network, path characterisation information indicative of at least one measure of a dynamic network characteristic at a remote node (23) outside said data network. The method involves a traffic management module (26) receiving at least one data unit from a remote node (23) outside said data network, and in the event that said at least one data unit is encapsulated in an outer header and that an inner header of said data unit includes path characterisation information, performing the following in respect of said data unit: (a) monitoring said path characterisation information in said inner header; and (b) forwarding said data unit according to a first treatment category. In the event that these conditions are not met, the data unit is instead subjected to an alternative treatment.
摘要:
Methods and an associated traffic management module and system are disclosed for monitoring, at a traffic management module (26) within a data network, path characterisation information indicative of at least one measure of a dynamic network characteristic at a remote node (23) outside said data network. The method involves a traffic management module (26) receiving at least one data unit from a remote node (23) outside said data network, and in the event that said at least one data unit is encapsulated in an outer header and that an inner header of said data unit includes path characterisation information, performing the following in respect of said data unit: (a) monitoring said path characterisation information in said inner header; and (b) forwarding said data unit according to a first treatment category. In the event that these conditions are not met, the data unit is instead subjected to an alternative treatment.
摘要:
A packet network is arranged into a hierarchy, having one organization-level portion (CS, P, R2) and three site-level portions (S1, S2, S3). By using forwarding computers and assigning multicast addresses in respect of each portion, the total number of multicast addresses required to send multicast messages to all possible subsets of potential recipients is reduced. This alleviates routers in the network of the burden associated with storing and processing a large amount of multicast addresses.
摘要:
Methods and apparatus are disclosed for obtaining and processing information from a predetermined portion of a header of a data item such as an IP packet transmitted via a communication network such as a packet network, the portion carrying a codepoint selected from a first set of codepoints each of which has a pre-defined meaning according to a first pre-defined communication protocol. The method comprises: receiving the data item; inspecting the header whereby to determine the codepoint carried by the predetermined portion thereof; identifying whether the codepoint is a member of a second set of codepoints, the second set comprising fewer possible codepoints than the first set; and in the event that the codepoint is identified as being a member of the second set, and in dependence on such an identification being made, interpreting that codepoint according to a different pre-defined communication protocol as having a different pre-defined meaning and routing the data item via the communication network via the second pre-defined communication protocol.
摘要:
Methods and apparatus are disclosed for obtaining information from a predetermined portion of a header of a data item such as an IP packet transmitted via a communication network such as a packet network, the portion carrying a codepoint selected from a first set of codepoints each of which has a pre-defined meaning according to a first pre-defined communication protocol. The method comprises: receiving the data item (s71); inspecting the header whereby to determine the codepoint carried by the predetermined portion thereof (s72); identifying whether the codepoint is a member of a second set of codepoints (s77, s78), the second set comprising fewer possible codepoints than the first set; and in the event that the codepoint is identified as being a member of the second set, and in dependence on such an identification being made, interpreting that codepoint according to a different pre-defined communication protocol as having a different pre-defined meaning (s80).