Cisco ISR 4321 vs Catalyst 8200 (C8200-1N-4T)
The ISR 4321 is winding down its lifecycle, and the Catalyst C8200-1N-4T is its modern SD-WAN-first replacement with a faster multicore CPU, higher encrypted throughput, and a single NIM plus 4 GE ports. Migrate to the C8200 for Catalyst SD-WAN and a longer support runway.
Cisco ISR 4321 Integrated Services Router
Branch ISR 4000 router with 2 GE WAN/LAN ports, 2 NIM slots, and IOS XE with optional SD-WAN.
- 2x GE (RJ45/SFP) + 2 NIM slots
- ~50 Mbps to 100 Mbps aggregate throughput (licensed)
- IOS XE, supports Cisco SD-WAN
- ISR 4000 generation; nearing EoL
Cisco Catalyst 8200 Edge Platform
Current-gen SD-WAN branch router with 4 GE ports, 1 NIM slot, and a multicore CPU on IOS XE 17.x.
- 4x GE WAN/LAN + 1 NIM slot
- Higher encrypted (IPsec) throughput
- Catalyst SD-WAN (vManage) native
- DNA/Catalyst licensing, current support
Cisco ISR 4321 Integrated Services Router vs Cisco Catalyst 8200 Edge Platform: spec comparison
| Spec | Cisco ISR 4321 Integrated Services Router | Cisco Catalyst 8200 Edge Platform |
|---|---|---|
| Onboard interfaces | 2x GE (RJ45 + SFP combo) | 4x GE (RJ45) |
| Module slots | 2x NIM | 1x NIM |
| Aggregate throughput | Up to ~100 Mbps (performance license) | Up to several hundred Mbps to ~1 Gbps |
| CPU | Multicore (ISR 4000 gen) | Newer multicore (Catalyst 8000 gen) |
| Default DRAM | 4 GB (expandable) | 8 GB (expandable) |
| Onboard PoE | Optional via internal power | Optional via internal power |
| Software | IOS XE 16.x/17.x | IOS XE 17.x |
| SD-WAN | Cisco SD-WAN (Viptela) supported | Catalyst SD-WAN native (vManage) |
| Licensing | ISR throughput / SD-WAN licenses | Cisco DNA / Catalyst tiered licensing |
| Management | vManage / CLI / Prime | vManage / Catalyst Center / CLI |
Choose Cisco ISR 4321 Integrated Services Router if
Only choose the ISR 4321 if you have an existing ISR 4000 fleet with two NIMs in use and need a matching spare short-term; it is a prior-generation platform nearing end-of-life.
Choose Cisco Catalyst 8200 Edge Platform if
Choose the C8200-1N-4T for new branch and SD-WAN deployments: more onboard GE ports, higher encrypted throughput, the latest IOS XE, and Catalyst SD-WAN with a current support lifecycle.
Verdict
For new branch routers, deploy the Catalyst C8200-1N-4T. It supersedes the ISR 4321 with a faster CPU, higher IPsec throughput, four onboard GE ports, and native Catalyst SD-WAN on current IOS XE, while the ISR 4321 is a prior generation nearing end-of-life. Keep the 4321 only where you need a matching spare or a second NIM slot temporarily.
Frequently asked questions
What is the replacement for the Cisco ISR 4321?
The Catalyst 8200 Edge Platform, specifically the C8200-1N-4T, is the modern successor to the ISR 4321 for branch routing and SD-WAN.
Does the Catalyst 8200 support Cisco SD-WAN?
Yes. The C8200 runs Catalyst SD-WAN managed by vManage natively on IOS XE 17.x, the same fabric the ISR 4321 could join with SD-WAN licensing.
How many NIM slots does the C8200-1N-4T have versus the ISR 4321?
The C8200-1N-4T has one NIM slot plus four onboard GE ports, whereas the ISR 4321 has two NIM slots and two onboard GE ports.
Is the ISR 4321 TAA compliant for federal use?
Cisco offers TAA-compliant configurations of both the ISR 4000 and Catalyst 8200 for US federal buyers; for new GPC-payable orders the C8200 is the recommended current platform.
More ISR comparisons
Specs are for planning and may change; Uniqcli confirms the current Cisco bill of materials and pricing on your quote. Cisco, Catalyst, Nexus, Meraki, and Firepower are trademarks of Cisco Systems, Inc.; Uniqcli LLC is an independent authorized Cisco partner.