This section describes the capabilities of the High Scale QoS (HSQ) IOM. The HSQ IOM is an FP3-based IOM that has a multicore CPU and accepts up to two MDA-e cards. The HSQ IOM supports an enhanced egress QoS traffic manager architecture to provide scalable network, service, and subscriber QoS. At ingress, the HSQ IOM supports regular FP3 QoS with a high ingress policer scaling.
The HSQ IOM (iom4-e-hs) supports six scheduling classes across multiple hierarchical levels of hardware egress shaping with very stringent egress burst control. The scheduling allows a mix of strict priority and weighted round-robin (WRR) queues. A flexible buffer pool structure allows both buffer isolation and buffer oversubscription for the queue buffer allocation.
The HSQ IOM supports 768k queues, which are grouped into 96k queue groups; each comprises eight queues (referred to as HSQ queue groups). HSQ queue groups are used for SAP and subscriber egress queues, network egress queues, and both access and network egress queue group instance queues.
The components of the HSQ IOM operation are described in subsequent sections.