1. A network server configured for operation in a telecommunication network, and further configured for detecting occurrences of a defined sequence of data symbols in a data stream flowing within the telecommunication network, the data stream comprising a plurality of data symbols representing characters of an alphabet, said network server comprising: an interface configured to receive the data stream; and a computer processor configured to: provide successive data symbols from the data stream as input data symbols to a deterministic finite automata that is implemented via the computer processor and configured to drive to one or more accepting states responsive to receiving the defined sequence of data symbols and otherwise to drive to one or more non-accepting states, wherein each input data symbol triggers the deterministic finite automata to transition from a current state to a next state in dependence on which character in the alphabet the input data symbol represents; and reduce an amount of memory required to implement the deterministic finite automata by implementing the deterministic finite automata using a compressed state transition register, wherein, for each defined state in the deterministic finite automata, the compressed state transition register includes register entries that define the next state to be transitioned to from a current state, in dependence on which character is represented by the current input data symbol, and wherein at least one register entry is a ranged entry that spans a range of characters in the alphabet that, for the current state, all map to a same next state.