I have looked over the book "End-to-End QoS Network Design" by Tim Szigeti et al. and RFC4594. The RFC proposes 14 Service class:
I have a switch with simple QoS features. It has 14 egress queues on each port and you can only configure weights in weighted round robin scheduler for these queues. No bandwidth allocation and RSVP are available. Is there any standard or suggestion or usual way of setting these weights? I couldn't find any weight suggestion for these queues over the internet. (My switch has 8 egress queues on each port actually but, there are no standard weights for the 8-queue model either. If I reached weights for the 14-queue model, it's not difficult to remap them into the 8-queue model and recalculating weights)
Update: Thanks @Marc'netztier'Luethi for his comment, it seems there are 12 service classes in the RFC 4954.