Router 4-port switch GigE WAN ports: 2

Additional information




Cisco C931-4P Router Overview


The Cisco 900 Series Integrated Services Routers (ISR 900) combines WAN, comprehensive security, and advanced connectivity in a compact, fanless platform. The routers are designed to provide enterprise-class security and connectivity for small to medium businesses. The ISR 931 model comes with a 4-port managed switch, providing LAN ports to connect multiple devices and up to 250 Mbps of VPN throughput for high performance. These small, yet powerful, fixed-configuration routers provide secure broadband and Metro Ethernet connectivity. The routers deliver integrated security and threat defense, protecting networks from both known and new Internet vulnerabilities and attacks.


WAN interfaces2 ports Gigabit Ethernet (GE)
LAN interfaces4-port GE managed switch
Maximum crypto throughput (bit-rate policed)250 Mbps
Integrated USB 2.0Yes
Default and maximum DRAMDefault 1 GB
Default and maximum flash memory2 GB; not upgradable
Dimensions (H x W x D)1.70 x 9.0 x 9.5 in. (4.32 x 22.86 x 24.13 cm) (includes rubber feet)
IP and IP services  Routing Information Protocol Versions 1 and 2 (RIPv1 and RIPv2)

  Generic Routing Encapsulation (GRE) and Multipoint GRE (MGRE)

  Cisco Express Forwarding

  Standard 802.1d Spanning Tree Protocol

  Layer 2 Tunneling Protocol (L2TP)

  L2TP Version 3 (L2TPv3)

  Network Address Translation (NAT)

  Dynamic Host Configuration Protocol (DHCP) server, relay, and client

  Dynamic DNS

  DNS Proxy

  DNS Spoofing

  Access Control Lists (ACLs)

  IPv4 and IPv6 multicast

  Open Shortest Path First (OSPF)

  Border Gateway Protocol (BGP)

  Performance Routing (PfR)

  Enhanced Interior Gateway Routing Protocol (EIGRP)

  Virtual Route Forwarding (VRF) Lite

  Next Hop Resolution Protocol (NHRP)

  Bidirectional Forwarding Detection (BFD)

  Web Cache Communication Protocol (WCCP)

xDSL  True Multimode VDSL2 and ADSL2+ over Annex A, B, J, and M, including traditional G.DMT and T1.413

  World-class interoperability with industry-standard DSL Access Multiplexer (DSLAM) chipsets

  Highest field reliability with Impulse Noise Protection (INP) over Repetitive Electrical Impulse Noise (REIN) and single isolated impulse noise (SHINE), extended INP delay, G.INP, physical layer retransmission, Seamless Rate Adaptation (SRA), and Bitswap

  VDSL2 Persistent Storage Device (PSD) profiles up to 17a/b with support for spectral shaping

  VDSL2 vectoring to offer blazing fiber speeds over copper

  Remote management with TR069 and CWMP

  Investment protection with Gigabit Ethernet

Switch features  Auto Media Device In/Media Device Cross Over (MDI-MDX)

  25 802.1Q VLANs

  MAC filtering

  Switched Port Analyzer (SPAN)

  Storm control

  Smart ports

  Secure MAC address

  Internet Group Management Protocol Version 3 (IGMPv3) snooping


Security featuresSecure connectivity:

  Secure Sockets Layer (SSL) VPN for secure remote access

  Hardware-accelerated DES, 3DES, AES 128, AES 192, and AES 256

  Public-Key-Infrastructure (PKI) support

  50 IPsec tunnels

  Cisco Easy VPN client and server

  NAT transparency

  Dynamic Multipoint VPN (DMVPN)

  Tunnel-less Group Encrypted Transport VPN (GET VPN)

  VRF-aware IPsec

  IPsec over IPv6

  Adaptive control technology

  Session Initiation Protocol (SIP) application-layer gateway

  Cisco IOS Firewall:

   Zone-based policy firewall

   VRF-aware stateful inspection routing firewall

   Stateful inspection transparent firewall

  Advanced application inspection and control

  HTTPS, FTP, and Telnet Authentication Proxy

  Dynamic and static port security

  Firewall stateful failover

  VRF-aware firewall

  Cisco IOS Software black and white lists

  Integrated threat control:

   Intrusion Prevention System (IPS)

  Control plane policing

  Flexible packet matching

  Network foundation protection

Quality of Service (QoS)  Low-Latency Queuing (LLQ)

  Weighted Fair Queuing (WFQ)

  Class-Based WFQ (CBWFQ)

  Class-Based Traffic Shaping (CBTS)

  Class-Based Traffic Policing (CBTP)

  Policy-Based Routing (PBR)

  Class-Based QoS MIB

  Class of Service (CoS)-to-Differentiated Services Code Point (DSCP) mapping

  Class-Based Weighted Random Early Detection (CBWRED)

  Network-Based Application Recognition (NBAR)

  Link Fragmentation and Interleaving (LFI)

  Resource Reservation Protocol (RSVP)

  Real-Time Transport Protocol (RTP) header compression (cRTP)

  Differentiated Services (DiffServ)

  QoS preclassify and prefragmentation

  Hierarchical QoS (HQoS)

Management  Cisco Configuration Professional

  Cisco Configuration Express

  Cisco Configuration Engine support

  Cisco AutoInstall

  Cisco IP Service-Level Agreement (IP SLA)

  Cisco IOS Embedded Event Manager (EEM)


  Cisco Security Manager

  Telnet, Simple Network Management Protocol Version 3 (SNMPv3), Secure Shell (SSH) Protocol, Command-Line Interface (CLI), and HTTP management


  Cisco Next-Generation Plug-and-Play (NG PnP) Protocol

High availability  Virtual Router Redundancy Protocol (VRRP) (RFC 2338)



Metro Ethernet  Ethernet OA&M

  Ethernet Local Management Interface (E-LMI)

  IP SLA for Ethernet

IPv6  IPv6 addressing architecture

  IPv6 name resolution

  IPv6 statistics

  IPv6 translation: Transport packets between IPv6-only and IPv4-only endpoints (NAT-Protocol Translation)

  Internet Control Message Protocol Version 6 (ICMPv6)




  IPv6 Path Maximum Transmission Unit (PMTU)

  IPv6 neighbor discovery

  IPv6 stateless address autoconfiguration (SLAAC)

  IPv6 multicast routing

Application visibility and control  NBAR2

  Flexible NetFlow (FNF)

  Performance Agent

Number of recommended users50
Default and maximum DRAMDefault 1 GB
Default and maximum flash memory  2 GB on all Cisco 900 Series ISR models; not upgradable
WANRefer to Table 2 for details
LAN switchRefer to Table 2 for details
Separate console portsRJ-45
USB 2.0  One USB 2.0 Type A port
Physical dimensionsH x W x D = 1.70 x 9.0 x 9.5 in. (4.32 x 22.86 x 24.13 cm) (includes rubber feet)
Power supplyPower specifications:

  AC input voltage: Universal 100 to 240 VAC

  Frequency: 50 to 60 Hz

  Internal power supply (C921-4P and C931-4P only)

Approvals and complianceSafety:

  IEC 60950-1

  UL 60950-1

  CAN/CSA C22.2 No. 60950-1

  EN 60950-1

  AS/NZS 60950.1

  Class I Equipment (C921-4P and C931-4P only)

  Class III Equipment (C927-4P, C927-4PM, and C926-4P only)


  47 CFR Part 15: 2006

   CISPR22: Edition 6.0: 2008

   CNS13438: 2006

   EN 300 386 V1.6.1

   EN 55032

   EN61000-3-2: 2006 [+ amd 1 & 2]

   EN61000-3-3: 2008

   ICES-003 Issue 5: 2012

   KN 22: 2009

  TCVN 7189: 2009

  VCCI: V-3/2012.04


  CISPR24: 2010 [+ amd 1 & 2]

   EN300386: V1.6.1

   EN55024: 2010

   EN61000-6-1: 2007

   KN24: 2011

   TCVN 7317:2003

Environmental operating range  Nonoperating temperature: -40 to 158F (-40 to 70C)

  Nonoperating humidity: 5% to 95% relative humidity (noncondensing)

  Nonoperating altitude: 0 to 15,000 ft (0 to 4570 m)

  Operating temperature: 0 to 50C (de-rate 1C per 1000-ft increase in altitude)

  Operating humidity: 5% to 95% relative humidity (noncondensing)

  Operating altitude: 0 to 10,000 ft (0 to 3000 m)




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