1. A method for compressing packet headers for transmission across a telecommunications network, the method comprising: establishing a plurality of flows in the telecommunications network, a path of each flow including a first network node functioning as a compressor and a second network node functioning as a decompressor; assigning, at the compressor, a context identifier to each flow, wherein a length of each context identifier for a first subset of the flows is a first number of bits and a length of each context identifier for a second subset of the flows is a second number of bits greater than the first number of bits; receiving, at the compressor, a packet associated with a new flow, wherein a value of a context identifier assigned to the new flow must fit within the first number of bits; determining that the context identifiers for the plurality of flows have occupied all values within the first number of bits; assigning, at the compressor, a context identifier to the new flow, wherein the context identifier assigned to the new flow is the context identifier previously assigned to an identified flow in the second subset; and assigning a new, unoccupied value for the context identifier of the identified flow in the second subset.