A method for performing a measurement on data traffic at a node (Ni) of a communication network (CN), said node (Ni) comprising at least an input interface (Iin1) and an output interface (lout2), said method comprising, at said input interface (Iin1), receiving first data units (Pk1) of said data traffic and: a) for each received first data unit (Pk1), checking whether said first data unit (Pk1) is marked by a feature (b2) set to any value selected from a first value and a second value; b) implementing a global input parameter (X1 ) and, if said first data unit (Pk1) is marked, updating said global input parameter (X1 ) when said feature (b2) is set to said first value; and c) implementing a partial input parameter (X12 ) relating to said output interface (lout2) and updating said partial input parameter (X12 ) when said feature (b2) is set to said first value and when said first data unit (Pk1) is addressed to said output interface (lout2), said method further comprising, at said output interface (lout2), receiving second data units (Pk2) of said data traffic, said second data units (Pk2) comprising at least part of said first data units (Pk1), and: d) for each received second data unit (Pk2), checking whether said second data unit (Pk2) is marked by said feature (b2) set to any value selected from said first value and said second value; e) implementing a partial output parameter (Y12 ) relating to said input interface (Iin1) and, if said second data unit (Pk2) is marked, updating said partial output parameter (Y12 ) when said feature (b2) is set to said first value and when said second data unit (Pk2) is received from said input interface (Iin1); and f) implementing a global output parameter (Y2 ) and updating said global output parameter (Y2 ) when said feature (b2) is set to said first value, said method further comprising: g) at said node (Ni), performing a measurement relating to said data traffic within said node (Ni) based on said partial input parameter (X12 ) and said partial output parameter (Y12 ). a) for each received first data unit (Pk1), checking whether said first data unit (Pk1) is marked by a feature (b2) set to any value selected from a first value and a second value; b) implementing a global input parameter (X1 ) and, if said first data unit (Pk1) is marked, updating said global input parameter (X1 ) when said feature (b2) is set to said first value; and c) implementing a partial input parameter (X12 ) relating to said output interface (lout2) and updating said partial input parameter (X12 ) when said feature (b2) is set to said first value and when said first data unit (Pk1) is addressed to said output interface (lout2), d) for each received second data unit (Pk2), checking whether said second data unit (Pk2) is marked by said feature (b2) set to any value selected from said first value and said second value; e) implementing a partial output parameter (Y12 ) relating to said input interface (Iin1) and, if said second data unit (Pk2) is marked, updating said partial output parameter (Y12 ) when said feature (b2) is set to said first value and when said second data unit (Pk2) is received from said input interface (Iin1); and f) implementing a global output parameter (Y2 ) and updating said global output parameter (Y2 ) when said feature (b2) is set to said first value, <EOS>