The Difference Between MAP-T and CGNAT

This article provides a summary of everything you need to know about MAP-T – including its basic principles, practical applications, and how Incognito can help you capitalize on it.

Published on July 21, 2023

Overcome IPv4 Exhaustion and Prepare for IPv6 with MAP-T

In the vast and ever-expanding landscape of the Internet, IP addresses are the lifeblood that allows devices to communicate and connect with each other. IPv4 has served as the foundation for routing data for decades, but the rapid growth of online usage has led to a shortage. At one time, the world's nearly 4.3 billion IPv4 addresses seemed like plenty, but in a highly connected world where every stationary and mobile device has an IP address, it's amazing how quickly 4.3 billion can go. Like most problems, IPv4 exhaustion has solutions, but that doesn't mean they're simple.

What can operators do?

  1. Seek to acquire IPv4 addresses to expand their existing resource pool. However, at $32 USD per address— and rising—that's a costly proposal.
  2. Migrate from IPv4 to IPv6. Long-term, this is coming – and Incognito can help you get there. For now, though, the Internet isn't ready for IPv6 only; some aspects of IP communications still rely on IPv4. And the magnitude of the migration process means it's not a practical short-term plan.
  3. Extend existing IPv4 investment while planning for IPv6 migration. This is the approach many operators will pursue, but even this option leads to more choices which we explain next.


CGNAT – Stateful solution

CGNAT (carrier-grade NAT) was developed specifically to address IPv4 exhaustion by allowing multiple subscribers to share. Unfortunately, like a stateful solution, CGNAT is hardware-intensive and costly. Because CGNAT tracks the state of every single lease, session, IP address assignment, and more, it has significant CPU, database, and memory requirements.

MAP-T – Stateless solution

Enter Mapping of Address and Port-Translation (MAP-T). This primarily stateless technology extends IPv4 in a similar way to CGNAT, with a much less costly deployment because there's no requirement for a server to keep track of every single session and address assignments and availability, and it provides v4-v4 connectivity over a v6 domain.

MAP-T sounds like a great solution, and you may be wondering if there's a catch. Well, for large-scale deployment, MAP-T requires special IPv6 configurations by the DHCP server. The good news is that Incognito's Broadband Command Center (BCC 8.0) supports those specialized configurations.

Automating complex DHCPv6 settings

  1. Open-source DHCP servers: While open source may seem like a cost-cutting approach, it's not carrier-grade, and you have to maintain it yourself, so the savings you want may not materialize.
  2. Broadband network gateway (BNG) or broadband remote access server (B-RAS): These tools may seem well suited for the task, but they're not vendor agnostic and may lock you in.
  3. Incognito's Broadband Command Center: By automating complex DHCPv6 settings, Incognito's proven, carrier-grade BCC product can help you extend your IPv4 investment with MAP-T automation while preparing you to deploy IPv6 at scale.

Simplify configuration settings with Incognito BCC

Incognito's carrier-grade BCC platform can automate configurations for operators to easily introduce MAP-T at scale in the following ways:

  • DHCPv6 complex options for MAP-T
    • DHCPv6 option 95; sub-options 89, 91, 93
    • Multiple data types in the sub-options
  • DHCPv6 link address criteria—v6 gateway
    • Client class
    • Device classifier

MAP-T is a technology telecom operators can use to extend the life of their valuable IPv4 resources. Although the method is similar to CGNAT, this technology is "stateful" and requires a large hardware investment. As a primarily stateless solution, MAP-T is less costly to deploy. However, it requires some special configurations by the DHCPv6 server to be deployed on a large scale. BCC 8.0 now supports those specialized configurations.

To find out how our solution can help you address your IPv4/IPv6 challenges in the most efficient way possible, visit our solution page.

Incognito Broadband Command Center

Incognito's Broadband Command Center is the industry's leading independent DOCSIS provisioning solution offering automated end-to-end device provisioning and management for cable and fiber networks, increased network security, and centralized DHCP in a single platform. Learn how Incognito's holistic solution supports network growth and reduces costs.

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