Cisco NCS-55A1-36H-S / NCS-55A1-36H-SE-S vs Arista DCS-7500R2AK-36CQ-LC
Posted by Isuf Tjeglla on Aug 28th 2025
Here's a polished side-by-side comparison between the Cisco NCS-55A1-36H-S / NCS-55A1-36H-SE-S and the Arista DCS-7500R2AK-36CQ-LC line card—highlighting their key distinctions, ideal use cases, and strengths:
Cisco vs Arista: Feature Comparison
| Feature | Cisco NCS-55A1-36H-S / SE-S | Arista DCS-7500R2AK-36CQ-LC |
|---|---|---|
| Product Type | Fixed 1U routing chassis | Modular line card for 7500R2 series chassis |
| Ports | 36 × QSFP28 (100G/40G native, 25/10G via breakout) | 36 × QSFP100 (100G native; supports 10/25/40/50/100G) |
| Throughput | Up to 3.6 Tbps, ~3,340 MPPS | ~3.34–4.32 Bpps (depending on buffer) |
| Routing Scale | Base: 1M FIB; SE-S variant: 4M FIB entries | ~2M IPv4/IPv6 routes via FlexRoute + AlgoMatch |
| ASIC / TCAM | Jericho+ ASIC; SE-S adds external TCAM for scale | AlgoMatch-enhanced architecture for flexible matching |
| Buffering | On-chip and off-chip buffers for high throughput needs | ~16 GB packet buffer memory (large deep buffering) |
| MACsec Support | Full line-rate encryption across all ports | Optional—depending on variant (not standard in this model) |
| Power Consumption | Base: ~1100 W typical / ~1450 W max; SE-S: ~1300 W / ~1700 W | ~830 W typical / ~921 W max |
| Form Factor | Standalone 1U chassis | Pluggable line card (requires a compatible chassis) |
| Software / Features | Runs Cisco IOS XR with rich automation & telemetry | Compatible with Arista EOS; AlgoMatch for ACL, PBR, telemetry |
| Ideal Deployment | Enterprise cores, service provider regional routing | Data center spine/leaf, high-density modular switching |
Insights by Category
Product Architecture & Flexibility
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The Cisco NCS is a complete routing appliance—compact and ready for deployment out of the box.
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The Arista card is a modular component, optimized for high-density data center environments when paired with a supporting chassis.
Performance & Scalability
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Both systems deliver robust throughput and packet forwarding capacity suitable for demanding environments.
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Cisco offers dual scale tiers: the SE-S variant is geared for massive routing tables (up to 4 million entries).
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Arista’s AlgoMatch + FlexRoute delivers flexible pattern matching and routing at around 2 million entries, ideal for large-scale routing with enhanced ACL/direction logic.
Security & Encryption
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Cisco provides full line-rate MACsec encryption across all ports.
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Arista supports MACsec, but it isn't explicitly integrated in this specific variant.
Buffering & Latency Handling
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The Arista line card includes large deep packet buffers, beneficial for handling bursty traffic and smoothing latency.
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Cisco also utilizes buffering strategies (on-chip and off-chip) built to maintain high throughput with low latency.
Power & Efficiency
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Cisco's SE-S model consumes more power due to its enhanced scale.
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Arista’s card is more power-efficient, making it attractive for environments where energy budget is a concern.
Software Ecosystem
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Cisco runs on IOS XR, offering advanced programmability, telemetry, and automation toolkit.
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Arista integrates with EOS, and benefits from AlgoMatch for access control policies and policy-based routing.
Summary: When to Choose Which
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Choose Cisco NCS-55A1-36H-S (or SE-S variant) if:
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You need a self-contained, high-performance routing platform.
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You require full-line encryption.
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Your network demands extremely large routing tables (SE-S variant).
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You depend on Cisco’s IOS XR ecosystem for automation and telemetry.
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Choose Arista DCS-7500R2AK-36CQ-LC if:
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You already operate within an Arista 7500R2 modular switching chassis.
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You need high-density, flexible-speed port configurations.
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Your setup benefits from large packet buffers and AlgoMatch capabilities.
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You seek a more power-efficient option for dense data center deployments.
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