Patent ID: 8027269
Filing Date: 2011-09-27
Classification: H04L

Abstract:
1. An arrangement for determining mutual differences of transmission delays experienced by received protocol data units and for performing control actions related to ingress ports of a network element, each protocol data unit being associated with an order indicator arranged to indicate the position of that protocol data unit in a mutual sequential order of said protocol data units, and each protocol data unit being sent earlier than or simultaneously with a protocol data unit next in said sequential order, the arrangement comprising: a processor unit arranged to: determine, based on a first order indicator associated with a first protocol data unit received earlier and a second order indicator associated with a second protocol data unit received later, whether the first protocol data unit is later in said sequential order than said second protocol data unit, said first protocol data unit being a protocol data unit received at a first ingress port of the network element, and said second protocol data unit being a protocol data unit received at a second ingress port of said network element, and in response to a situation in which said first protocol data unit is later in said sequential order than said second protocol data unit, calculate a time difference of receiving moments of said second protocol data unit and said first protocol data unit, said time difference representing a lower limit for a difference between transmission delays experienced by said second protocol data unit and said first protocol data unit wherein said processor unit is further arranged to remove said second ingress port from among ingress ports available to a routing protocol in response to a situation where said first protocol data unit is later in said sequential order than said second protocol data unit and an indicator value updated on the basis of said time difference exceeds a predetermined threshold value.