Broadcom Qumran Architecture
The Broadcom Qumran family is tailored for access and aggregation routers. While it shares DNX architecture roots with Jericho, Qumran ASICs are typically deployed in fixed-form platforms.
Overview
Unlike Jericho, which is suited for fabric-connected modular chassis, Qumran often handles the entire routing pipeline on a single chip, though some variants can be fabric-attached. It is widely utilized in equipment taking 100G/400G down to 1G/10G endpoints layer, such as the Cisco NCS 5000, NCS 540, and various Nokia platforms.
Generations and Buffer Characteristics
- Qumran-MX / AX: Standardly equipped with an integrated 16 MB to 32 MB on-chip packet buffer. Deployed in environments requiring dense 10G/100G MAC capabilities but fewer prolonged microbursts (e.g., Cisco NCS 5000).
- Deep Buffer Variants: Some Qumran families provide external DRAM integration—scaling buffer pools into the gigabytes range (e.g. up to 3 GB in the Cisco NCS 540) to effortlessly accommodate speed mismatches where large inbound 100G streams must squeeze down into 1G or 10G tail circuits.
- Virtual Output Queueing (VOQ): Most Qumran deep-buffer chips employ VOQ scheduling to ensure fairness and prevent head-of-line blocking under extreme congestion.