what is Jericho+ with NG eTCAM (large-scale LPM)

Jericho+ with NG eTCAM (Large-Scale LPM)

1. Jericho+ ASIC

• Jericho+ is a high-performance network processor ASIC developed by Broadcom, used in many carrier-class routers and switches (Cisco, Juniper, Nokia, etc.).

• It’s designed for high-scale routing (service provider backbones, internet edge, data center interconnects).

• Features include:

  • Massive throughput (multi-terabit per second).

  • Large table sizes for routing and MPLS.

  • Built-in features for QoS, traffic management, and telemetry.

• Think of Jericho+ as the core “brain” that moves packets at line rate while handling advanced routing features.

2. eTCAM (External Ternary Content-Addressable Memory)

• TCAM is a special type of memory used in networking gear to store entries like:

  • Forwarding Information Base (FIB, i.e., routes),

  • Access Control Lists (ACLs),

  • Policy rules,
    and allow for fast lookups in O(1) time (one operation regardless of table size).

• External TCAM (eTCAM): Since the ASIC’s on-chip resources are limited, external TCAM expands storage capacity for these entries.

• The “NG” (Next Generation) eTCAM is Broadcom’s enhanced version:

  • Provides much larger scale for routing tables.

  • More efficient use of memory (compression/optimized storage).

  • Higher density and lower power per entry than older eTCAM.

3. Large-Scale LPM (Longest Prefix Match)

• In IP routing, packets are forwarded based on the longest prefix match (LPM) in the routing table.

  • Example: Packet destined for 192.168.1.45 → router checks FIB and matches the most specific route (say /28) rather than a broader /16.

• “Large-scale LPM” means the system can store and quickly search through millions of IPv4/IPv6 prefixes for this longest-match process.

• With NG eTCAM, Jericho+ ASICs can support multi-million-entry LPM tables, enabling routers like Cisco’s NCS-55A1-36H-SE-S to handle global internet routing tables with headroom for growth.

Putting it Together

• Jericho+ ASIC alone → great performance, but limited to ~1M FIB entries.

• Jericho+ with NG eTCAM → offloads lookups to external, optimized memory, pushing scalability to 4M+ routes.

• This is why Cisco markets the SE-S (Scale Enhanced) model — it includes NG eTCAM to handle very large routing environments like Tier-1 ISPs or global service providers.

✅ In short:
Jericho+ with NG eTCAM = a Broadcom-based architecture that uses external next-gen TCAM to massively increase the size of routing and policy tables, enabling large-scale internet routing with fast longest-prefix match.