How to Analyze Router Diversity in ISP Networks Using Real Measurements

In this blog, we explore how researchers study router diversity using Internet measurements. By examining how different vendors respond to probes and analyzing large datasets, we gain valuable insights that benefit students working on networking projects or seeking computer network assignment help.

Why Router Diversity Matters

Routers form the backbone of the Internet. Every packet that leaves your device and travels across the world passes through multiple routers—sometimes dozens—on its path to the destination.

These routers perform essential tasks such as:

• Forwarding packets based on routing tables
• Handling congestion
• Managing TTL (Time-To-Live) values
• Generating ICMP messages
• Running routing protocols such as OSPF, IS-IS, or BGP

However, not all routers behave the same way. Different vendors implement different internal architectures, different protocol stacks, and even different default parameter values. Some vendors focus on high-performance backbone routers, while others specialize in access or edge devices. This results in networks where multiple types of routers coexist.

Industry analysts often publish market-share studies that show the popularity of vendors in the global router market. These reports provide a high-level understanding of vendor dominance. But market statistics alone cannot reveal how ISPs actually deploy routers internally. That is where Internet measurement studies provide deeper, more technical insights.

Two recent studies—based on the content provided—use measurement techniques such as ICMP analysis, traceroute probing, and banner collection via ssh, telnet, and SNMP to infer which routers are deployed in large ISPs. These methods help build a detailed picture of router diversity inside real networks.

Fingerprinting Routers Using ICMP TTL Behavior

One major technique presented in the content is router fingerprinting based on ICMP message behavior. When routers respond to certain network probes, they generate ICMP messages with specific TTL values. These TTL values vary by vendor and operating system, creating a “signature” that can be used to identify the router type.

The study “Network Fingerprinting: Routers under Attack” analyzes these ICMP characteristics in detail. Using traceroute-like measurements, the researchers observe the values of TTL in ICMP time exceeded or echo-reply messages.

Based on earlier observations, the following vendor-specific TTL behaviors are known:

• Cisco routers use a TTL of 255 when sending ICMP time-exceeded or echo-reply messages.
• Juniper routers running JUNOS use a TTL of 255 for ICMP time-exceeded messages but 64 for echo-reply messages.
• Brocade, Alcatel, and Linux-based routers typically use a TTL of 64 when sending ICMP time-exceeded or echo-reply messages.

These differences, though subtle, are extremely useful. When performing traceroute probing across ISP networks, thousands of ICMP messages are collected. By analyzing their TTL values, researchers can infer which router vendors appear at each hop.

This technique allows us to observe vendor distribution in networks without needing credentials, access permissions, or internal topology information. It is a passive and scalable way to understand the structure of Internet routers.

What Traceroute Reveals About Router Diversity

Using these TTL-based signatures, the study concludes that ISPs use routers from different vendors, and the diversity can be visualized across Autonomous Systems (ASes). The figure you provided (Figure 4 in the source content) shows the hardware popularity per AS.

The chart reveals that:

• Some ISPs rely heavily on Cisco hardware
• Others combine Cisco with Junos-based routers
• Some ASes include a mix of Cisco, JunosE, BAL, or other devices
• A few ASes show the presence of additional categories labeled as “Others”

This confirms that router diversity is not only real but widespread.

From a student’s perspective, this means:

• Traceroute results may differ not just because of network conditions but also because routers behave differently depending on the vendor
• ICMP patterns can be used as tools to infer network characteristics in assignments or research
• Network behavior cannot be generalized based on a single vendor’s products

Understanding these differences gives deeper insight into Internet topology and helps interpret real measurements more accurately.

Classifying Network Vendors Using Banner Collection

Another study mentioned in the content—“Classifying Network Vendors at Internet Scale”—takes a different measurement approach. Instead of focusing on TTL-based signatures, this work inspects ssh, telnet, and SNMP banners.

Many routers expose limited interface banners over management protocols. These banners may reveal:

• Vendor name
• Operating system information
• Device series
• Hardware identifiers

By systematically collecting and classifying these banners, the study constructs a large dataset mapping IP addresses to router vendors.

This method complements the ICMP fingerprinting technique. While ICMP analysis captures routers responding to probes, banner collection identifies routers reachable via management interfaces. Together, these methods provide a richer understanding of router landscapes across the Internet.

What Large-Scale Measurements Reveal About Router Distribution

The second image you provided, a labeled dataset table, shows the inferred vendor distribution based on two approaches:

1. Regex Match of IP Address Labels
2. Clustering-Based Labeling
3. Final Network Device Labels After Filtering Unresponsive Addresses

The table includes rows for manufacturers such as:

• Cisco
• Mikrotik
• Huawei
• H3C
• NEC
• Lancom
• Juniper
• Adtran
• ZTE
• Ubiquoss
• Dell

The numbers indicate the volume of labeled routers in each category.

For example:

• Cisco dominates the dataset with 63,990 matches via regex labeling and 85,379 matches via clustering, with 83,592 responsive devices after filtering.
• Mikrotik appears heavily in the clustering approach with 39,243 matches.
• Huawei and H3C also appear in significant numbers.
• Vendors such as NEC, Ubiquoss, and Dell appear far less frequently, showing their smaller footprint in global router deployments.

This dataset, even though simplified, highlights an important fact: ISP networks consist of a broad mix of routers, each with its own role and capabilities.

Why ISPs Use Routers From Different Vendors

An important takeaway for networking students is understanding why ISP networks are so diverse. There are several technical and economic reasons:

Functional Specialization

Different routers are optimized for different tasks:

• Core routers handle high-speed backbone traffic
• Edge routers manage customer access
• Aggregation routers combine traffic from multiple links

Vendors often excel in particular segments, so ISPs mix different hardware to meet performance requirements.

Cost Optimization

Routers vary significantly in price. ISPs balance high-end hardware with more cost-effective alternatives.

Reliability and Redundancy

Using multiple vendors reduces dependence on a single supplier and protects networks from:

• Firmware bugs
• Security vulnerabilities
• Supply chain disruptions

Legacy Deployments

Routers remain in service for years. Networks naturally evolve into multi-vendor environments due to phased upgrades.

Operational Flexibility

Some vendors offer better support for certain protocols or integration features, encouraging ISPs to mix equipment.

Understanding these factors helps students appreciate why real-world networks look much more diverse than textbook examples.

Implications for Students and Networking Assignments

At computernetworkassignmenthelp.com, we frequently assist students with assignments related to routing, traceroute analysis, network mapping, and device classification.

The router diversity insights from these studies provide several valuable lessons:

Traceroute Interpretation

Students must recognize that:

• Different vendors respond to probes differently
• ICMP TTL behavior affects traceroute hop count interpretation
• Routers may suppress or modify responses depending on vendor settings

Router Fingerprinting in Assignments

Students can incorporate TTL-based signatures to:

• Infer router types in traceroute outputs
• Analyze ISP paths
• Study multi-vendor deployments

Network Measurement Projects

Whether in academic labs or capstone projects, students may perform:

• Active probing
• Passive banner collection
• Topology reconstruction

Understanding vendor diversity allows students to interpret these results more accurately.

Understanding Real-World Network Complexity

Assignments often simplify routing to make concepts easier to learn. But real networks:

• Mix protocols
• Mix hardware
• Use custom configurations

This complexity is important when working on advanced networking topics, such as congestion control, BGP analysis, or backbone network design.

How Router Diversity Shapes the Internet

Based on the observations from the provided content, we see a clear pattern: the Internet is built on a heterogeneous collection of routers deployed by ISPs to meet diverse operational needs.

This diversity:

• Enhances network resilience
• Enables scaling across global infrastructures
• Allows flexibility in deployment strategies
• Reflects decades of technological evolution

But it also poses challenges:

• Troubleshooting becomes more complex
• Standardization becomes harder
• Security behaviors vary
• Measurement artifacts appear in traceroute results

These challenges make the field exciting and create opportunities for research, innovation, and continuous improvement.

Conclusion

Router diversity is a fundamental characteristic of real-world ISP networks. Through ICMP fingerprinting techniques and banner-collection methodologies, researchers uncover how routers from different vendors coexist within the same network.

The provided figures and datasets illustrate that ISPs deploy routers from Cisco, Juniper, Huawei, Mikrotik, H3C, Adtran, ZTE, and many others. These measurements reveal the true complexity of the Internet and highlight why students studying networking must go beyond theoretical protocol analysis.

At computernetworkassignmenthelp.com, we emphasize the importance of connecting textbook knowledge with real-world data. Understanding router behavior, vendor diversity, and Internet-scale measurements equips students with the skills needed to excel in their networking coursework, research, and future careers.

If you need help analyzing traceroute data, understanding routing behavior, or preparing a detailed networking assignment, our expert team is always here to support you.