CISCO ISR4351 Router

Well, we are today discussing on a new router named as Cisco ISR 4351 which cisco launches newly in the market. The cisco 4351 is very robust router and fills the gap between the Cisco 3900 series router and Cisco ASR routers. 

We faces various issues like we have the required WAN bandwidth more than 150 Mbps or 200 Mbps which cisco model we gonna take, we are confused with the Cisco 3900 series here, although Cisco 3900 series is capable of handling this much of traffic but still we want something which can further capable of increasing the bandwidth till 400 Mbps.

There are lots of demand coming from the Enterprise customers where the traffic increases day by day and due to the lack of the cisco WAN router model enterprise solutions are going away from Cisco.

Cisco thought and come up with the new series model which is Cisco ISR 4300 and Cisco ISR 4400 Series router as they both are under Cisco 4000 Series family group.

There are other models aswell in Cisco portfolio for this much of the bandwidth like if you are talking about the another cisco model named Cisco 4451-X, it can go till 1 Gbps of WAN bandwidth and can solve the gap between the 400 Mbps till 1 Gbps. So you can increase the bandwidth and also choose the cisco router model as per the need of the WAN bandwidth.

We have various recommendations like i can summarise some of them in the below description, although you can have the more bandwidth supported in these router but i recommended this much of the bandwidth for these below routers as:

From 2 Mbps to 20 Mbps : You can use Cisco 1900 Series router
From 21 Mbps to 80 Mbps : You can use Cisco 2900 Series router
From 80 Mbps till 150 Mbps : You can use Cisco 3900 Series router
From 200 Mbps till 400 Mbps : Cisco 4351 router is good to go
From 400 Mbps till 1 Gbps : Cisco 4451-X router is perfect
From 1 Gbps to 2.5 Gbps : Cisco ASR 1001 router ( End of sale )
From 1 Gbps till 20 Gbps Backplane traffic : ASR 1001-X or ASR 1002-X can be used.

These above are only the recommendations but you can use much more traffic from these routers as tested in the labs but i am sure the live environment is something different from the labs.

Now lets discuss about the Cisco 4351 router which is under the portfolio of Cisco 4000 Series router product.

The Cisco 4351 is suggested for migration from existing Cisco 2951 routers. It offers 200-Mbps performance (100Mbps port speed),upgradable to 400 Mbps (200Mbps port speed), in a 2RU form factor with 3 NIM slots and 2 SM slots.
● 8-core CPU with 4 data-plane cores, 1 control-plane core, and 3 cores dedicated for services

● Single or double-wide Cisco UCS E-Series support, and up to 16-GB control and services memory.

Fig 1.1- Cisco 4351 Router


Cisco ISR 4300 Series IOS XE Universal – SISR4300UK9-313S or SISR4300NPEK9-313S (ISR4351/K9 only)
Cisco ISR 4351 AX Bundle with APP and SEC license
2 single- or 1 double-wide – 1-port clear-channel T3/E3 service module used foused for T3/E3. The Maximum Number of T3/E3 Modules Supported are 2. 
10 (4 10/100/1000 built into chassis) (Ethernet Routed-Port)  and additional 48 if SM-X Layer 2/3 EtherSwitch Service Module used.

Fig 1.2 - Cisco Router 4351 front View

Multiple VPN will enable the CPE to be VLAN aware and support Customer VLAN Tagging (802.1q) and as such enable mapping between VLANs to VPNs. The only rule is that a VPN can map to many VLANs but a VLAN can only map to a single VPN (this is done to maintain supremacy of VPNs within the IP Connect Global network).
The recommendations provided above are based on testing performed using 400 byte data packets and 60 byte voice packets.  Higher throughput may be achievable if customers are using larger packets


9 (3 10/100/1000 built into chassis) (Ethernet Routed-Port)  and 50 if SM-X Layer 2/3 EtherSwitch Service Module used.

Fig 1.3 - Cisco Router 4351 View



Note : The performance of  FL-4350-PERF-K9  13% at 100M down to 2% of port speed at 150M


Note – ADSL/VDSL/SHSDL/ISDN interfaces are not yet available for the 4000 series routers.
The PoE module can be enabled on two of the on board front-panel Gigabit Ethernet ports. A POE Module for On Board GE for Cisco ISR 4451-X, 4431 & 4351 is required as a prerequisite.