Juniper M40 Internet Backbone Router: the first internet router to utilise ASCI’s

With many parts available with quick lead times, TXO has one of the largest ranges of parts and components for the Juniper M40 Internet Backbone Router. We also offer a repair and refurbishment service for many components within the Juniper M-series family of routers as well as offering help and advice to support your existing network equipment including network adaptors, server motherboards and hard drives.

Get in touch with our multilingual team who will be happy to help support your needs.


Availability and shipping for the Juniper M40

At TXO we have one of the largest selections of Juniper M40 components available to order with fast lead times. Most Juniper M40 parts will be dispatched immediately on receipt of purchase order and delivered within 1-3 days in the UK and 3-5 days for international delivery.


About the Juniper M40

The Juniper M40 Backbone Internet Router was launched in 1998 by Juniper Networks, Inc. as the first of their successful M Series of multiservice edge routers. The M Series also included other internet routers such as the M10, M20 and M160. The Juniper M40 was developed to keep up with the greater amount of wireless traffic which was passing through the routers of the time. The M40 router was unique in the fact that at the time it was the only router to successfully utilise Application Specific Integrated Circuits (ASIC’s), which allowed the router to perform its core functionality quicker than with ordinary microprocessors.

When initially released the Juniper M40 was equipped with a system specific System Control Board (SCB) which held the Internet Processor i. Future iterations of the router were deployed with the Internet Processor ii ASIC which better addressed the ACL capability of the unit. The FCB monitors system components, processes exception and control packets, and performs sampling, filtering and packet forwarding decisions. As will all Juniper routers, the Juniper M40 runs the Junos OS operating system. 

One of the key reasons the Juniper M40 was a success was that it split the functionality of the control plane and forwarding plane. The first was used to quickly and efficiently forward packets to their destination as quickly as possible, which in the case of the M40 is up to 40 million packets per second. The latter handled where individual packets were to be sent. Splitting this functionality helped prevent bottlenecks during packet handling. 

Unlike other routers within the Juniper M-Series, the M40 has no component redundancy capability such as dual power supplies found in the M20. This was addressed when the M40e router was released in 2002, which kept the same packet forwarding ability of the M40, but allowed for the additional system redundancy found within other routers of the M-Series. 

As with many Juniper Internet routers, ease of use was critical to the success of this product, several modules were field-replaceable, meaning key components of the router could be added or changed on-site by the operator with minimal downtime to the router. On the M40, the routing engine, cooling system, PIC’s, power supply, craft interface, SCB and FPC were all capable of being replaced without the need to shut down the router and interrupt its operations. This level of flexibility made the Juniper M40 popular amongst network operators as it removed the need for costly on-site engineer visits in the event of an issue or upgrade. 

In March 2003 Juniper Networks announced the end of life of the M40 background router as 30th September 2008, after which point the OEM would no longer offer support or technical assistance to users. TXO continues to repair damaged parts for the Juniper M20 router as well as offering technical advice on this product. 


Juniper M40 component list

At TXO we have an extensive range of new and refurbished products and parts for the Juniper M40 Internet Backbone Router. A list of some of the most popular products can be found below, but please contact us if the part you require is not listed.


Part numberDescriptionHECI
SCB-M40Juniper M40 Control Board
FAN-M40-SJuniper M40 Single Fan
PWR-M40-ACJuniper M40 AC Power Supply
PWR-M40-DCJuniper M40 DC Power Supply
M40-FPC1Juniper M40 Flexible PIC Concentrator
IPI2LMJAAAJuniper M40 4 port DS3 PIC Card
P-4E3-ATMJuniper M40 4 Port ATM E3 PIC Card
I-1OC48-SON-SMIR-EJuniper M20 M40 1 Port STM OC 48 Interface Card
RE-333-768Juniper M40 Routing Engine
P-4T1-RJ48Juniper M40 4 Port T1 PICIPI4LBKBAA


Contact us

Repair capability for the Juniper M40 Internet Backbone Router

As part of the TXO mission to support the circular economy and to help minimise the environmental impact of telecoms across the supply chain, we offer an extensive and comprehensive third-party repair service that focuses on lifecycle management across a wide range of components for the Juniper M40 Backbone Internet Router as well as other routers from the Juniper M Series range. 

Based out of our advanced engineering facilities in Solihull, our team of experienced system engineers have an in-depth knowledge of core telecom repairs including optical, IP and radio based technologies at circuit board level and conduct approximately 12,000 repairs each year. This ensures the businesses we work with can maintain optimum service levels and minimise disruption to their network. At TXO we are able to refurbish and restore many components for the Juniper M40 router alongside many others from the M-Series of routers as well as assisting in the procurement of replacement parts as necessary. 

To help ensure the longevity of the repairs we carry out and the overall life of your Juniper M40, we will often conduct several pre-emptive repairs as part of the service we offer. By reconditioning and repairing parts that are susceptible to developing faults we can help prevent any future repairs by refurbishing parts before issues develop.  

For occasions where minimal downtime is required, we also offer an advance replacement service for many used Juniper M40 parts, which allows us to deliver components to you in advance of a repair being carried out, allowing you to ensure that there is minimal disruption to your business. 

View the full list of platforms we repair. Alternatively, you can contact us to discuss your individual needs. 


Technical Specifications for the Juniper M40

For full details of the Juniper M40 platform please view the full OEM datasheet.


Hardware Specifications
Chassis height35 in. (89 cm)
Chassis width19 in. (48 cm)
Chassis depth23.5 in. (60 cm)
Weight, max. config280 lb (127 kg)
Weight, min. config.180 lb (81 kg)
Thermal output3850 BTU/hour
AltitudeNo performance degradation to 10,000 ft. (3048 m)
Relative humidityNormal operation ensured in relative humidity range of 5% to 90% non condensing
TemperatureNormal operation ensured in temperature range of 0°C (32°F) to +40°C
SeismicShock Tested to meet Bellcore Zone 4 earthquake requirements
DC Power Specs.
Maximum power output1500 W
Input voltage–40 through –75 VDC operating range
Input current rating35A @ 48V
Output voltage+3.3V, +5V, +2.5V, +12V, +24V
AC Power Specs.
Maximum power output1500 W
input voltage180–264 VAC operating range
Input line frequency50–60 Hz, autoranging
Input current rating8A @ 208V
Output voltage+3.3V, +5V, +2.5V, +12V, +24V


Please note, TXO is an independent retailer and has no affiliation with Juniper Networks, Inc. or any of its associated companies.