A multi-port access node (100; 150; 200) for communicating data to-and-fro a plurality of transceiver units via a plurality of respective communication lines, the multi-port access node comprising: a plurality of multiple distribution point unit,DPU, processors (106 1,...,106 4; 158 1,...,158 4; 200 1, 200 2) forming a cascade configuration defining a first processor (106 1; 158 1; 202 1), each of the plurality of processors includes a main communication unit (120 1, 102 2; 202; 202 1, 202 2), said main communication unit includes a network-side port (106 1,...,106 4; 214; 124 1, 124 2, 170 1,...,170 4; 200 1, 200 2), each of the plurality of processors includes at least one line-side port (216; 216 1,...,216 8) associated with a respective one of said communication lines, at least one of said processors further includes a relay unit (122 1, 122 2; 204 1, 204 2) having a relay port (126 1, 126 2; 174 1, 174 2, 174 3; 218; 218 1, 218 2), said relay unit is coupled with said main communication unit of the same said processor, said relay port is coupled with at least one said network-side port of at least one different said processor, wherein said first processor is configured to aggregate a flow-control state associated with each of said processors in said cascade configuration, wherein each of said processors is configured to generate its respective local PAUSE data that said processors relay through the hierarchy of said cascade configuration toward said first processor that is configured to combine said local PAUSE data with its own local PAUSE data, wherein said relay unit is configured to facilitate relaying at least part of said data in at least one of a downstream direction destined toward at least one of said transceiver units, and an upstream direction arriving from at least one of said transceiver units. a plurality of multiple distribution point unit,DPU, processors (106 1,...,106 4; 158 1,...,158 4; 200 1, 200 2) forming a cascade configuration defining a first processor (106 1; 158 1; 202 1), each of the plurality of processors includes a main communication unit (120 1, 102 2; 202; 202 1, 202 2), said main communication unit includes a network-side port (106 1,...,106 4; 214; 124 1, 124 2, 170 1,...,170 4; 200 1, 200 2), each of the plurality of processors includes at least one line-side port (216; 216 1,...,216 8) associated with a respective one of said communication lines, at least one of said processors further includes a relay unit (122 1, 122 2; 204 1, 204 2) having a relay port (126 1, 126 2; 174 1, 174 2, 174 3; 218; 218 1, 218 2), said relay unit is coupled with said main communication unit of the same said processor, said relay port is coupled with at least one said network-side port of at least one different said processor, wherein said first processor is configured to aggregate a flow-control state associated with each of said processors in said cascade configuration, wherein each of said processors is configured to generate its respective local PAUSE data that said processors relay through the hierarchy of said cascade configuration toward said first processor that is configured to combine said local PAUSE data with its own local PAUSE data, wherein said relay unit is configured to facilitate relaying at least part of said data in at least one of a downstream direction destined toward at least one of said transceiver units, and an upstream direction arriving from at least one of said transceiver units.