Hello, There is different types for the Cisco 7600 Series Ethernet Services cards. ( More expensive cards with high queue values and less expensive cards with low queue values.) http://www.cisco.com/en/US/prod/collateral/routers/ps368/data_sheet_c78-5494... Hardware queues ES Plus XT 40G line cards • 128,000 ingress queues • 256,000 egress queues ES Plus XT 20G line cards *• 64,000 ingress queues* • 128,000 egress queues Hierarchical QoS (H-QoS) http://www.cisco.com/en/US/prod/collateral/routers/ps368/data_sheet_c78-5707... Hardware queues Cisco 7600 Series ES Plus Transport 40G and 20G Line Cards *Supporting up to 16 level 4 queues per physical port* Hierarchical QoS (H-QoS) Low queue cards have got only 4 queues per physical port. High queue cards have got minimum 64.000 queue. This is very huge difference. In what kind of scenario do we have to use the High queue cards ? Could you give some examples please ? Kind Regards. Burak