Disclosed are methods and arrangements in a VoIP access node for handling downstream and upstream RTP packets associated with an ongoing VoIP call. One common IP address can be assigned to the all of the RTP traffic of an access node instead of assigning one IP address per VoIP card. This may be done by identifying the destination VoIP card based on the destination UDP port number in a received RTP packet. The number of public IP addresses needed for VoIP service may be reduced without increasing the cost of the access node.