Model Comparison: ISR 4321 vs. 4331 vs. 4351 vs. 4431 vs. 4451 Router

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The Cisco ISR 4000 Series is still a hot topic when users select a router to set up a better network.

How to find out the very right Cisco 4000 router for your branch office? Let’s read the main model comparison of Cisco ISR 4000 routers.

The 4000 Series contains five platforms: the 4451, 4431, 4351, 4331, and 4321 ISRs.

Model Comparison: ISR 4321 vs. 4331 vs. 4351 vs. 4431 vs. 4451 Router

Feature	4321	4331	4351	4431	4451
Form factor	1 rack unit (RU) Desktop	1 RU	2 RU	1 RU	2 RU
Integrated WAN ports	1 GE / SFP 1 GE	1 GE / SFP 1 GE 1 SFP	2 PoE GE / SFP 1 GE/ SFP	2 PoE GE / SFP 2 GE / SFP	2 PoE GE / SFP 2 GE / SFP
Performance	50 Mbps Upgradable to 100 Mbps	100 Mbps Upgradable to 300 Mbps	200 Mbps Upgradable to 400 Mbps	500 Mbps Upgradeable to 1 Gbps	1 Gbps Upgradable to 2 Gbps
Management port	1 GE (Integrated Out of Band)
Network Interface Modules (NIM)	2	2	3	3	3
Enhanced Services Module (SM-X)	N/A	1 single-wide	2 single- or 1 double-wide	N/A	2 single- or 1 double-wide
Integrated Services Card (ISC) slots	1 (PVDM 4)	1 (PVDM 4)	1 (PVDM 4)	1 (PVDM 4)	1 (PVDM 4)
USB ports (type A)	1	1	2	2	2
Default/max Flash	4 GB / 8 GB	4 GB / 16 GB	4 GB / 16 GB	8 GB / 32 GB	8 GB / 32 GB
Default/max DRAM	4 GB / 8 GB	4 GB / 16 GB	4 GB / 16 GB	4 GB / 16 GB	4 GB / 16 GB
Power supply type	External: AC, PoE	Internal: AC, PoE	Internal: AC, PoE or DC	Internal: AC, PoE or DC	Internal: AC, PoE or DC
Redundant power supply	No	No	No	Yes Internal RPS	Yes Internal RPS
Module online insertion and removal (OIR)	Yes	Yes	Yes	Yes	Yes
Server virtualization platform (UCS E-Series)	N/A	2-core single-wide, 4-core single-wide	2 core single-wide, 4 core single-wide, 4 core double-wide, 6 core double-wide, 8 core double-wide	N/A	2-core single-wide, 4-core single-wide, 4-core double-wide, 6-core double-wide, 8-core double-wide
Advanced Security	4321	4331	4351	4431	4451
Zone-based firewall and NAT services	VRF-Aware Firewall and Network Address Translation (NAT)
Hardware VPN acceleration (DES, 3DES, AES)	No
IPSEC VPN services	FlexVPN, Easy VPN remote server, Enhanced Easy VPN, Dynamic Multipoint VPN (DMVPN), Group Encrypted Transport VPN (GET VPN), V3PN, MPLS VPN
SSL VPN	No
Intrusion prevention	Yes
Network foundation protection	ACL, FPM, control plan protection, control plane policing (CoPP), QoS, role-based CLI access, source-based RTBH, uRPF, SSHv2
Cisco Cloud Web Security	Yes*
Identity-based networking	No	No	No	No	No
Cisco TrustSec	Security Group Tag Exchange Protocol (SXP), SGT over GETVPN SGT over IPSEC SGT over DMVPN SGT-based ZBFW Port/Layer 3 interface/IP/subnet-to-SGT mapping SGT export in Flexible NetFlow
Unified Communications	4321	4331	4351	4431	4451
Local conferencing	Yes	Yes	Yes	Yes	Yes
Digital signal processor support	PVDM4	PVDM4	PVDM4	PVDM4	PVDM4
Cisco Unified Survivable Remote Site Telephony support	Up to 50	Up to 100	Up to 750	Up to 1200	Up to 2000
Cisco Unified Communications Manager Express support	Up to 50	Up to 100	Up to 250	Up to 350	Up to 450
Cisco Unity Express (NM, SM, or ISM)	Use Cisco Unity Connection on UCSE	Use Cisco Unity Connection on UCSE	Use Cisco Unity Connection on UCSE	Use Cisco Unity Connection on UCSE	Use Cisco Unity Connection on UCSE
Cisco Unified Border Element (CUBE) (SIP/H.323 sessions)	100	400	1000	3000	6000
nano Cisco Unified Border Element (nanoCUBE) (sessions)	N/A	N/A	N/A	N/A	N/A
Digital voice and video (T1/E1 channels)	Up to 240	Up to 360	Up to 720	Up to 720	Up to 1200
Analog/BRI voice	Up to 8 ports (FXS, FXO, E/M, BRi)	Up to 12 ports (FXS, FXO, E/M, BRi)	Up to 20 ports (FXS, FXO, E/M, BRi)	Up to 12 ports (FXS, FXO, E/M, BRi)	Up to 20 ports (FXS, FXO, E/M, BRi)
Routing and Multicast	4321	4331	4351	4431	4451
IPv4 routing protocols	RIP v1/v2, EIGRP, OSPF, BGP, PBR, PfR	RIP v1/v2, EIGRP, OSPF, BGP, PBR, PfR	RIP v1/v2, EIGRP, OSPF, BGP, PBR, PfR	RIP v1/v2, EIGRP, OSPF, BGP, PBR, PfR	RIP v1/v2, EIGRP, OSPF, BGP, PBR, PfR
Multicast routing protocols	PIM-SM, mroute (static route), and MLD	PIM-SM, mroute (static route), and MLD	PIM-SM, mroute (static route), and MLD	PIM-SM, mroute (static route), and MLD	PIM-SM, mroute (static route), and MLD
IPv6 routing protocols	EIGRP, RIP, OSPFv3, IS-IS, BGP and PBR	EIGRP, RIP, OSPFv3, IS-IS, BGP and PBR	EIGRP, RIP, OSPFv3, IS-IS, BGP and PBR	EIGRP, RIP, OSPFv3, IS-IS, BGP and PBR	EIGRP, RIP, OSPFv3, IS-IS, BGP and PBR
Wireless LAN	4321	4331	4351	4431	4451
Integrated 802.11 b/g/n access point	N/A	N/A	N/A	N/A	N/A
Integrated 802.11 a/b/g/n access point	N/A	N/A	N/A	N/A	N/A
Unified and autonomous mode	N/A	N/A	N/A	N/A	N/A
RP-TNC connectors for field-replaceable optional high-gain antennas	N/A	N/A	N/A	N/A	N/A
Diversity (dual antennas)	N/A	N/A	N/A	N/A	N/A
Wireless LAN controller module	Available on UCS E-Series	Available on UCS E-Series	Available on UCS E-Series	Available on UCS E-Series	Available on UCS E-Series
Wireless WAN	4321	4331	4351	4431	4451
3G /4G LTE cellular	Yes*
Outdoor antennas	N/A	N/A	N/A	N/A	N/A
Integrated Switching	4321	4331	4351	4431	4451
Maximum switched Ethernet ports	N/A	24	48	N/A	48
Maximum switched Ethernet LAN ports with PoE	N/A	24	48	N/A	48
PoE support (wattage) without PoE boost	120 W	250 W	500 W	250 W (with optional power supply redundancy)	500 W (with optional power supply redundancy)
PoE support (wattage) with PoE boost	260 W	530 W	990 W	500 W (no power supply redundancy)	950 W (no power supply redundancy)
EtherSwitch Service Module type (width)	N/A	1 single	2 single or 1 double	N/A	2 single or 1 double
Application Services	4321	4331	4351	4431	4451
Intelligent Path Control	PfR	PfR	PfR	PfR	PfR
Network Contention Control	QoS, HQoS	QoS, HQoS	QoS, HQoS	QoS, HQoS	QoS, HQoS
Application Visibility	NBAR v2	NBAR v2	NBAR v2	NBAR v2	NBAR v2
WAN Optimization	ISR-WAAS	ISR-WAAS, vWAAS on UCS E-Series	ISR-WAAS, vWAAS on UCS E-Series	ISR-WAAS	ISR-WAAS, vWAAS on UCS E-Series
Akamai Connect	Yes	Yes	Yes	Yes	Yes
Cisco Application Centric Infrastructure	Application Policy Infrastructure Controller (APIC) with Enterprise Module