The Cisco ASA series remains one of the most trusted names in network security. Even today, its hardware firewalls are known for reliability, stability, and strong VPN support. Among them, the Cisco ASA 5505 and Cisco ASA 5520 are the most requested models for office rentals.
Both share the same security foundation but are designed for very different setups. The ASA 5505 fits small offices and branch environments, while the ASA 5520 is made for mid-sized networks that handle heavier traffic and more users.
This guide offers a clear, verified Cisco ASA model comparison to help you choose the firewall that best fits your office network and performance needs.
Understanding the Cisco ASA Series
Cisco’s Adaptive Security Appliance (ASA) line became popular because it combines firewall, VPN, and intrusion prevention into one manageable unit. It provides unified threat defense without demanding large-scale infrastructure or complex configuration.
Both the ASA 5505 and the ASA 5520 are built on this foundation, delivering reliable perimeter security and secure remote access. The key difference lies in their performance capacity, scalability, and suitability for different user loads.
Cisco ASA 5505 – Compact Security for Small Teams
The Cisco ASA 5505 is purpose-built for small offices, startups, and branch environments. It offers business-grade protection in a compact form, making it ideal for smaller teams that need cost-effective security.
Key Specifications:
- Firewall throughput: Up to 150 Mbps
- VPN throughput: Up to 100 Mbps
- Concurrent sessions: 10,000 (base) to 25,000 with Security Plus license
- VPN peers: 10–25 IPsec peers (base to Security Plus); 2–25 SSL VPN users (base to Security Plus)
- Interfaces: 8 Fast Ethernet ports (2 with PoE support)
- VLANs: 3 by default, expandable up to 20 with trunking
- High availability: Basic redundancy supported with Security Plus
Why Rent the ASA 5505:
- Best suited for teams under 50 users
- Simple to manage via Cisco ASDM
- Affordable entry point for branch deployments
- Supports VoIP and external access points through PoE
Limitations:
- Limited VPN scaling and throughput
- Not ideal for environments with high concurrent traffic
- Does not support security contexts or virtual firewalls—unlike models such as the ASA 5520, the ASA 5505 cannot create separate compartmentalised policy zones within a single appliance. Multi-tenancy, departmental segmentation, and virtualization features are not available on this platform
The ASA 5505 remains a practical choice for small offices looking for an affordable Cisco firewall rental that still offers enterprise-grade reliability.
Cisco ASA 5520 – Mid-Sized Power for Growing Networks
The Cisco ASA 5520 builds on the same core technology but scales significantly higher. It is designed for medium-sized enterprises that require more throughput, user capacity, and network segmentation.
Key Specifications:
- Firewall throughput: Up to 450 Mbps
- VPN throughput: Up to 225 Mbps
- Concurrent sessions: Up to 280,000
- VPN peers: 750 IPsec (base platform) and up to 750 SSL VPN peers (with SSL VPN license upgrade)
- Interfaces: 4 Gigabit Ethernet + 1 Fast Ethernet
- VLANs: Supports up to 150 VLANs
- High availability: Active/Active and Active/Standby failover
- Virtualization: Up to 20 security contexts (with license; base system includes 2)
Why Rent the ASA 5520:
- Perfect for networks with 200+ users or distributed offices
- Strong VPN performance for remote teams
- Enables segmentation through VLANs and virtual contexts
- Supports clustering and load balancing for VPN scalability
Limitations:
- Higher rental cost than smaller models
- Requires skilled IT support for configuration and monitoring
If your network demands high uptime, multiple VPN users, or departmental segmentation, renting a Cisco ASA 5520 series firewall is a far more future-ready choice.
Cisco ASA 5505 vs Cisco ASA 5520: Model Comparison Table
| Feature | Cisco ASA 5505 | Cisco ASA 5520 |
|---|---|---|
| Firewall Throughput | Up to 150 Mbps | Up to 450 Mbps |
| VPN Throughput | Up to 100 Mbps | Up to 225 Mbps |
| Concurrent Sessions | 10,000–25,000 (with licences) | Up to 280,000 |
| VPN Peers (IPsec/SSL) | 10–25 / up to 25 (licenced) | Up to 750 (licenced) |
| Interfaces | 8 Fast Ethernet (2 PoE) | 4 Gigabit + 1 Fast Ethernet |
| VLANs Supported | 3–20 | Up to 150 |
| High Availability | Basic (with license) | Full Active/Active and Active/Standby |
| Virtual Firewalls | Not supported | Up to 20 security contexts (licenced) |
| Best For | Small offices and branches (<50 users) | Mid-sized enterprises |
| End-of-Sale Status | Aug 25, 2017 | Sept 16, 2013 |
| Last Date of Support | Aug 31, 2022 | Sept 30, 2018 |
Security, Support, and End-of-Life Status
Both models have officially reached End-of-Sale and End-of-Life (EoL) status as per Cisco’s notices. This means they no longer receive new software updates or bug fixes, though many organisations continue to use them for non-critical roles or controlled environments.
If you are considering these appliances, Cisco ASA model rentals make practical sense. Renting allows you to maintain a secure network perimeter without committing capital to legacy hardware, while also retaining the flexibility to upgrade to newer platforms like Cisco Firepower when required.
Important reminders:
- For compliance-sensitive environments, check whether EoL hardware meets audit requirements.
- For mission-critical setups, pair legacy ASA units with managed security services that provide continuous monitoring.
Which One Should You Rent?
Your choice should depend on the scale of your network and the level of performance you require.
- Choose ASA 5505 if you are a small office or startup with fewer than 50 employees. It is cost-effective, reliable, and covers the essentials.
- Choose ASA 5520 if you are a mid-size organisation managing remote access, heavy data transfer, or multiple departments. It provides higher throughput, redundancy, and scalability.
Why Rent Cisco ASA Firewalls from Rank Computers
At Rank Computers, we provide both the Cisco ASA 5505 and Cisco ASA 5520 series on flexible rental terms tailored to your IT needs.
With every Cisco firewall rental, you get:
- Quick delivery within 24–48 hours
- Expert configuration and setup support
- Upgrade flexibility as your network grows
- Custom pricing plans for small and mid-sized offices
Whether you want to test a security setup before a major upgrade or ensure consistent protection across multiple offices, our Cisco ASA model rentals offer a cost-efficient and reliable way to secure your network without heavy capital investment.
Get in touch today for a custom quote and secure your office network with the right Cisco firewall.
