Cisco NCS 5500 Series
The Cisco NCS 5500 Series is a high-density core/edge routing platform constructed using Broadcom Jericho and Jericho+ ASICs, known for their massive port density combined with deep external buffering.
Buffer Architecture
| Field | Value |
|---|---|
| Total Buffer | 16 MB On-chip + 4 GB to 8 GB Off-chip per ASIC |
| Buffer Model | Virtual Output Queueing (VOQ) |
| Off-chip Memory | GDDR5 deep buffers |
| Target Role | Core / Edge / Peering |
| Forwarding ASIC | Broadcom Jericho / Jericho+ |
Key Architectural Points
- The architecture merges a very fast but small 16 MB on-chip memory with a massive, somewhat slower GDDR5 off-chip memory pool (usually 4 GB or 8 GB depending on the line card).
- Uses Virtual Output Queueing (VOQ) exclusively. Packets are buffered at the ingress side before being requested over the fabric, eliminating head-of-line blocking.
- Allows for 50ms+ of packet memory even under extreme network congestion.
See the Broadcom Jericho Platform architecture page for deeper details on Jericho routing capabilities.