A method of estimating the rate of a digital subscriber line (L n) in a network, wherein the network comprises a plurality of digital subscriber lines and a plurality of distribution points, and each of the plurality of digital subscriber lines passes through one of the plurality of distribution points, said method comprising: (i) identifying a digital subscriber line to estimate the rate of, and determining a line characteristic value associated with said identified line, wherein the line characteristic is indicative of the length of the digital subscriber line; (ii) identifying the distribution point over which the identified digital subscriber line is carried; (iii) determining a quality figure for each of the plurality of digital subscriber lines, where each of the digital subscriber lines has an associated line characteristic value and line rate value, wherein the line characteristics associated with the plurality of lines are subdivided into a plurality of line characteristic bins, and wherein the quality figure for each of the plurality of digital subscriber lines is dependent on the line rate value associated with the respective digital subscriber line when compared to the line rate values of all the digital subscriber lines in the network in the same line characteristic bin; (iv) generating a population plan comprising the quality figure for each of the plurality of digital subscriber lines in the network together with the line characteristic value and line rate of the respective digital subscriber line; (v) determining a quality figure for the identified distribution point based on the quality figure of each of the digital subscriber lines passing through said identified distribution point; (vi) estimating the rate of the identified digital subscriber line by using the line characteristic value associated with said identified digital subscriber line, together with the determined quality figure of the identified distribution point, to look-up a line rate value from the population plan. (i) identifying a digital subscriber line to estimate the rate of, and determining a line characteristic value associated with said identified line, wherein the line characteristic is indicative of the length of the digital subscriber line; (ii) identifying the distribution point over which the identified digital subscriber line is carried; (iii) determining a quality figure for each of the plurality of digital subscriber lines, where each of the digital subscriber lines has an associated line characteristic value and line rate value, wherein the line characteristics associated with the plurality of lines are subdivided into a plurality of line characteristic bins, and wherein the quality figure for each of the plurality of digital subscriber lines is dependent on the line rate value associated with the respective digital subscriber line when compared to the line rate values of all the digital subscriber lines in the network in the same line characteristic bin; (iv) generating a population plan comprising the quality figure for each of the plurality of digital subscriber lines in the network together with the line characteristic value and line rate of the respective digital subscriber line; (v) determining a quality figure for the identified distribution point based on the quality figure of each of the digital subscriber lines passing through said identified distribution point; (vi) estimating the rate of the identified digital subscriber line by using the line characteristic value associated with said identified digital subscriber line, together with the determined quality figure of the identified distribution point, to look-up a line rate value from the population plan.