On 9/1/23 10:50, Saku Ytti wrote:
It is a very plausible theory, and everyone has this problem to a lesser or greater degree. There was a time when edge interfaces were much lower capacity than backbone interfaces, but I don't think that time will ever come back. So this problem is systemic. Luckily there is quite a reasonable solution to the problem, called 'adaptive load balancing', where software monitors balancing, and biases the hash_result => egress_interface tables to improve balancing when dealing with elephant flows.
We didn't have much success with FAT when the PE was an MX480 and the P a CRS-X (FP40 + FP140 line cards). This was regardless of whether the core links were native IP/MPLS or 802.1AX.
When we switched our P devices to PTX1000 and PTX10001, we've had surprisingly good performance of all manner of traffic across native IP/MPLS and 802.1AX links, even without explicitly configuring FAT for EoMPLS traffic.
Of course, our policy is to never transport EoMPLS servics in excess of 40Gbps. Once a customer requires 41Gbps of EoMPLS service or more, we move them to EoDWDM. Cheaper and more scalable that way. It does help that we operate both a Transport and IP/MPLS network, but I understand this may not be the case for most networks.
Mark.
