O'Reilly logo

Junos Enterprise Routing, 2nd Edition by Harry Reynolds, Doug Marschke, Peter Southwick

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

Routing Platforms

Over 15 years ago Juniper Networks designed their first Internet router. This device was unique in its packet processing power, low electrical power consumption, and small physical size. The reliability of the Junos operating system also became a selling point in the era of “reboot” troubleshooting. That initial router is the parent of the current M-series routers, and even though the M-series has gone through many revisions since the initial offering, they are still the “highest throughput for the least power in the smallest package” on the market today.

The M-series routers and their larger cousins, the T-series routers, offer service providers and enterprises a stable platform for routing IP traffic. They offer support for most standards-based routing protocols and support Layer 3 and Layer 2 provider-based VPN services.

The current lineup of the Juniper Networks M-series is:

M7i Multiservice Edge Router

10 Gbps of throughput makes this router a perfect edge device for SMB applications or Internet gateway or aggregation router for branch locations.

M10i Multiservice Edge Router

At 16 Gbps of throughput, this compact and redundant router provides a stable platform for growing enterprise networks.

M40e Multiservice Edge Router

This 40 Gbps platform offers flexibility and survivability for medium-sized enterprises.

M120 Multiservice Edge Router

With a throughput of 120 Gbps, this platform will support multimedia and service aggregation for an enterprise or service of any size.

M320 Multiservice Edge Router

The 320 Gbps throughput allows this platform to handle the largest backbone core routing and the most demanding multiplay applications.

The J-series routers were added to meet the demands of the smaller enterprise. The architecture of the J-series is slightly different than that of the M-series, in that the separation between the control plane and the forwarding plane is virtual rather than physical. In an M-series router, the packet-forwarding plane consists of specialized hardware designed for packet handling; in the J-series, the forwarding plane is a virtualized real-time thread with various application program interfaces and sockets modeling the specialized functionality. This difference allows Juniper to field a router with the same OS as the established M-series, but at a better price point for the enterprise. Firewall and security features have been added to the routing capabilities of the J-series routers.

The current Juniper J-series routers are:


Three PIM slots and 90 Mbps of throughput for routing and firewall features


Five PIM slots and 105 Mbps of throughput for routing and firewall features


Six PIM slots and 115 Mbps of throughput for routing and firewall features


Six PIM slots and 205 Mbps of throughput for routing and firewall features

The J-series routers are designed for enterprises that are connecting desktops to servers for office automation and back office applications. The Physical Interface Module (PIM) slots can be used for LAN connectivity, various WAN connectivity options (Serial, T1/E1, FE, DS3/E3, ISDN, ADSL2/2+, G.SHDS), and Avaya VoIP gateway and/or WAN acceleration.


With the advent of the SRX Series Services Gateways, the J-series routers are now preferred for their interface selection rather than performance or features.

Speeds and Feeds

Most of the routers fielded by Juniper are modular in design, allowing them to be configured for any role in the enterprise. The modular components add interface choices, service accelerators, and tunneling options to their base capabilities as routers. The available modules can be divided into various categories, each with supporting multiple port densities and interface speeds. The module categories are:

SONET/SDN physical interface cards (PICs)

Rates from OC-3 (155 Mbps) to OC-768 (40 Gbps)

Ethernet PICs

Rates from 100 Mbps to 10 Gbps, 1 port to 48 ports


E3, DS3, OC-3 to OC-48 ATM interfaces

Channelized PICs

E1, T1, DS3, OC-3, OC-12, and OC-48

Nonchannelized PICs

E1, T1, DS3, E3

Serial PICs

EIA-530, 2-port

Services PICs

Encryption Services (ES), Monitoring Services, Multiservices, Link Services, Tunnel



Ethernet PIMs

100 Mbps and 1 Gpbs copper and fiber

Services PIMs

Avaya Media Gateway, Juniper WXC WAN Accelerator


A full definition of each of these modules can be found at http://www.juniper.net/us/en/products-services/routing/m-series/m7i/#modules.

From an architectural perspective, these devices’ interface flexibility, protocol options, and scalable throughput allow the routers to be deployed in a collapsed backbone or a distributed core. The virtualization capabilities allow the routers to be placed in multitopology and multiclient environments, maintaining security via separation of traffic and services. Finally, the wide range of backplane speeds and throughputs (90 Mbps to 320 Gbps) allows a scalable and cost-effective Juniper router to be deployed for just about every network design.

MX Series 3D Universal Edge Routers

Juniper MX edge routers have the three dimensions required in today’s enterprises and service providers: scaling, availability, and agility. The first of these scaling factors is the maximum performance of the devices. The MX platforms support Ethernet traffic rates from 50 Mpps to 1.98 Bpps, allowing an MX platform to meet most routing and switching demands. Add to this the capability of arraying the MX in a virtual chassis, which reduces the management burden while increasing the connectivity capability compared to standalone switches. The mid-range MX line offers a pay-as-you-go scalability. The MX5 can be upgraded to the MX20, MX40, or the MX80 with the addition of a software license. This allows an enterprise to purchase the device that fits its needs today and migrate as those requirements grow.

The next dimension is the availability of the MX platform, which exceeds the Metro Ethernet Forum’s carrier grade switch specifications. The high-end MX platforms support redundant routing engines, redundant switching planes, virtual chassis operation, redundant power, and redundant cooling. Uptime is also maintained by the use of graceful restart, nonstop routing, fast reroute (FRR), unified in-service software upgrade (ISSU), and virtual private LAN switching (VPLS) multihoming.

The final dimension is the agility of the MX product line. The MX can perform routing and switching functions, and these platforms also support security features and virtualization features. This suite of capabilities allows the MX to operate as a core Ethernet switch, an MPLS edge router, an Ethernet aggregation point, or a distribution router. In many design scenarios, the agility of the MX allows multiple layers of a legacy design to be collapsed into a single layer. The addition of WAN optical interfaces to the MX expands its agility in the enterprise. No longer is the MX destined for the interior of the enterprise; it can operate as an enterprise edge device as well as an all-Ethernet core device.

The MX product line is composed of the following devices:

Mid-range MX

The mid-range chassis covers the MX5, MX20, MX40, and MX80 models. The chassis is a compact unit (3.5 inches high) with four built-in 10 Gbps Ethernet ports and up to two Modular Interface Cards (MICs). (The MX5 has a single MIC port.) The size and port density of the mid-range MX makes it ideal for small sites that need a feature-rich environment, such as mobile backhaul, metro Ethernet access, and field multimedia aggregation. Future support for virtual chassis will allow the mid-range MX to operate like the larger devices with redundant routing engines. The mid-range MXs are software upgradable, with the upgrade supporting higher throughput rates on the chassis. The MX80 also is available in a 48-port gigabit Ethernet configuration. The base throughput of the mid-range MXs starts at 20 Gbps for the MX5, 40 Gbps for the MX20, 60 Gbps for the MX40, and 80 Gbps for the MX80. All models handle 50 Mpps of mixed traffic.


The MX240 supports the MX feature set and adds survivability to the mix with redundant REs, switch fabric, power, and fans. This device can handle up to 480 Gbps of throughput and supports up to 120 gigabit Ethernet ports.


The 480 fills the need for high-density Ethernet aggregation in a survivable chassis. The platform can support 1.4 Tbps and a total of 240 GE ports. Each of the six card slots can handle 120 Gbps. The MX480 is designed to support large points of presence in enterprise networks.


At 2.6 Tbps, the MX960 can fill any role in a campus network that requires massive throughput. The throughput and feature set allows the MX960 to function at the core of the network as the Internet gateway for a campus or as an aggregation edge device for a large business park. The virtualization capabilities allow the MX960 to handle the traffic from multiple customers in a safe and dependable manner.

The MX edge routers support technologies and features that allow a separation between the physical deployment of devices and their logical capabilities. No longer is it necessary to deploy overlay networks for different services, different customers, or different media. By using network service virtualization (Layer 2 VPNs [L2VPN], Layer 3 VPNs [L3VPN], and virtual private LAN service [VPLS]), virtual devices (virtual chassis, virtual routers, and switching domains), and virtual link technologies (VLAN, link aggregation, pseudowire, and tunnels), the MX product line can act as any number of networks or devices, each providing a consistent quality of service (QoS) and security while increasing device utilization and lowering overall cost.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required