Cisco ASA 5520 Adaptive Security Appliance: a flexible and low-cost solution for SMB’s and enterprise businesses

TXO has one of the largest selections of components for the Cisco ASA 5520 Adaptive Security Appliance, with fast delivery available. We also offer a full third-party repair and refurbish service for many components within the Cisco 5500 series of security appliances, as well as offering ongoing help and advice for your existing Cisco architecture.

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


Availability and shipping for the Cisco ASA 5520

TXO is proud to stock a wide selection of Cisco ASA 5520 spare parts and components available for purchase, as well as many others in the Cisco 5500 series. Most 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 Cisco ASA 5520 Adaptive Security Appliance

The Cisco ASA 5520 Adaptive Security Appliance was released in 2005 by Cisco Systems, Inc. as part of their 5500 Series of network security devices which included, amongst others, the 5505, 5510, 5540 and 5550. The 5520 formed a key component in Cisco’s Self-Defending Network, designed to prevent security breaches before hitting the main network. The Cisco ASA 5520 incorporated a host of built in security features, such as an appliance firewall, VPN, intrusion prevention and advanced communications security services. 

Featuring four gigabit ethernet interfaces, the ASA 5520 was capable of supporting up to 100 VLAN’s by default with the option to scale this further depending on the requirements of the business. Network operators were able to cluster up to five 5520 units together, each of these were then capable of supporting  up to 750 SSL VPN peers, meaning a potential of 7500 VPN’s were achievable through one cluster.

The Cisco ASA 5520 was perfectly suited to deployment across multiple zones within a business network, which, combined with the option of scaling the amount of VLAN’s supported, made this platform popular for not only small and medium businesses, but even large and enterprise-sized businesses as well.

Utilising an Adaptive Inspection and Prevention (AIP) SSM, the Cisco ASA 5520 allowed network operators to tailor the security services required to different levels depending on the business area being supported, with the option to change intrusion prevention and content services as required. This level of control for the ASA 5520 security, gave network operators further added flexibility and security options to an already powerful platform. 

Cisco announced the end of life (EOL) of the ASA 5520 as 30th September 2018, after which point they would no longer offer support to operating using this appliance. TXO continues to offer repairs, support and guidance for businesses utilising the platform. Contact us today to find out how we can help with your existing Cisco architecture. 


Cisco ASA 5520 component list

At TXO we have an extensive range of refurbished products and parts for the Cisco ASA 5520 Security Appliance. 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
ASA5520-BUN-K9Cisco ASA 5520 Firewall Edition includes 4 Gigabit Ethernet interfaces + 1 Fast Ethernet interface, 750 IPsec VPN peers, 2 SSL VPN peers, Active/Active and Active/Standby high availability, 3DES/AES license
ASA5520-K8Cisco ASA 5520 Firewall Edition includes 4 Gigabit Ethernet interfaces + 1 Fast Ethernet interface, 750 IPsec VPN peers, 2 SSL VPN peers, Active/Active and Active/Standby high availability, DES licenseCOMMS00ARA


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Repair capability for the Cisco ASA 5520 Security Appliance

At TXO we believe we should aim to reduce the environmental impact of the telecoms sector across the supply chain, which is why we make it our mission to support the circular economy. As part of this, we offer a full third-party repair service that focuses on refurbishing and repairing many components for the Cisco ASA 5520, as well as many others across the Cisco ASA 5500 range. 

Our team of experienced system engineers based at our advanced engineering facilities in Solihull complete over 12,000 repairs every year. With an in-depth knowledge of core telecom repairs including optical, IP and radio-based technologies they are able to ensure the clients we work with can maintain optimum service levels and minimise disruption to the operation of their business. 

As part of our expert repair and refurbishment service, we will often conduct pre-emptive repairs to Cisco ASA 5500 components that are susceptible to developing faults. This helps prevent future repairs from being required and extends the longevity of your existing Cisco system. 

On top of our extensive range of parts available to order online, we are also able to procure replacement parts for the Cisco ASA 5520, if we don’t already have them available in stock. To ensure that you experience minimal disruption to your business operations, we also offer an advanced replacement service, where we deliver components to you before a repair is carried out, therefore ensuring minimal downtime. 

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


Technical specifications for the Cisco ASA 5520

For full details of the Cisco ASA 5520 Adaptive Security Appliance please view the full OEM datasheet.

Firewall ThroughputUp to 450 Mbps
Maximum Firewall and IPS Throughput● Up to 225 Mbps with AIP SSM-10
● Up to 375 Mbps with AIP SSM-20
● Up to 450 Mbps with AIP SSM-40
VPN ThroughputUp to 225 Mbps
Concurrent Sessions280,000
IPsec VPN Peers750
SSL VPN Peer License Levels*2,10, 25, 50, 100, 250, 500, or 750
Security Contexts*Up to 20
Integrated I/O4 Gigabit Ethernet ports and 1 Fast Ethernet port
Expansion I/O4 GE copper or 4 GE SFP
Virtual Interfaces (VLANs)150
ScalabilityVPN clustering and load balancing
High AvailabilityActive/Active**, Active/Standby
New Connections/
Security Contexts (Included/
Expansion Slot1 SSM
Number of User-Accessible Flash Slots1
USB 2.0 Ports2
Serial Ports2 RJ-45, console and auxiliary
Solid State DriveN/A
Memory2 GB
Minimum System Flash256 M/B
System BusMultibus architecture
Environmental Operating Ranges
Temperature32 to 104F (0 to 40c)
Relative Humidity5 to 95% noncondensing
AltitudeDeisgned and tested for 0 to 9840ft (3000m); agency approved for 2000m
Shock1.14m/sec (45in./sec) 1/2 sine input
Vibration0.41 Grms2 (3 to 500 Hz) random input
Acoustic Noise60 dBa max
AC Range Line Voltage100 to 240 VAC
AC Normal Line Voltage100 to 240 VAC
AC Current3A
AC Frequency47/63 Hz, single-phase
Dual Power SuppliesNone
Steady State150W
Maximum Peak190W
Maximum Heat Dissipation648 BTU/hr
Physical Specifications
Form Factor1 RU, 19-in. rack-mountable
Dimensions (HxWxD)1.75 x 17.5 x 14.25 in. (4.45 x 20.04 x 36.20 cm)
Weight (with power supply)20.0lb (9.07 kg)


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