Meet short-term CGNAT Capacity Requirements as work-at-home Traffic Surges

Meet short-term CGNAT Capacity Requirements as work-at-home Traffic Surges

The global pandemic has pushed Internet traffic up 50 percent or more in some markets and service providers are scrambling to increase capacity as subscribers work and play more at home and as enterprise shift to on-line business models. Service provider traffic has increased beyond expected trends in all categories and applications – voice, text/SMS, mobile, fixed, Internet, gaming, streaming video, video conferencing and more.  As mentioned in previous blog posts, service providers of all types, including mobile operators, ISPs, cable operators, and CDNs are reporting increases related to the pandemic.

Service providers are on the front lines of this crisis – maintaining the lifeline communications that connect people and businesses to critical services and we applaud the industry efforts to support their subscribers and communities in this time.

The capacity strain on networks is not limited to just an increase in required bandwidth. Service providers typically over-provision their networks to handle unexpected surges in traffic. So, for many, even this increase does not exceed provisioned capacity at least within the core elements or backbone. The problem for many operators is not so much the increased volume of traffic, but rather the distribution, or its impact on a few capacity-constrained technologies, such as IP address pools.

Ways traffic has changed and the potential impacts for service providers

In our conversations with service providers through this crisis, one identified area that is quickly getting overwhelmed is the carrier-grade network address translation (CGNAT) infrastructure – the capability in service provider networks that manages the pool of available IPv4 and IPv6 addresses. Let me explain why.

Operators maintain a pool of IP addresses that are shared amongst their subscribers and allocated as needed when subscribers access the network. A sudden increase in the number of subscribers requiring access or in the frequency of their use increases the load on that IP address pool. IPv4 addresses are a scarce resource – the free pool of IPv4 addresses was depleted in Sept. 2015. Additional addresses must be purchased through an auction and are quite expensive – having increased 4X over the last five years. While IPv6 addresses are in ready supply, 70 percent of internet queries still use IPv4, and many mobile or ISP networks are built around IPv4. So, for many service providers, augmenting depleted IPv4 address pools with IPv6 is simply not an option.

Carrier-grade network address translation technology, such as provided by A10 Thunder® CGN, helps service providers meet short-term capacity requirements, extending the life of IPv4 and helping with the transition to IPv6.

What is NAT and CGNAT?

Network address translation (NAT) technology appeared soon after internet use exploded in the early 1990s. The Internet Protocol (IP) version 4 addressing scheme was not designed to scale and IP address depletion became a serious issue. About this time, both IP version 6 (IPv6) and NAT appeared as solutions for this dilemma.

NAT provides a translation technology that allows multiple end customers to use common and overlapping private address ranges internally. Any number of end customers can use the same private address ranges. To route to external internet IP addresses, NAT translates private IP addresses to public IP addresses. Each customer could be provided a single or a small range of public IP addresses to support hundreds or thousands of internal machines.

CGNAT, also known as large-scale NAT (LSN), is an extension of traditional network address translation technologies for large-scale networks and internet service providers. CGNAT provides a solution to relieve IPv4 exhaustion and is an integral part of IPv6 migration. CGNAT provides the ability to share a global (public) IP address among multiple remote sites or devices. CGNAT was developed to allow ISPs to use public IP addresses to support ever more end customers.

The A10 Thunder CGN product helps service providers optimize existing CGNAT infrastructure, meet short term capacity requirements, extend the life of IPv4 and ipv6 to ipv4 transition. We have worked with several service providers during this critical time to augment their CGNAT capacity and meet the increased demand for services.

Additional Resources

Learn more about A10’s CGNAT solutions:



Terry Young
April 23, 2020

About Terry Young

Terry Young is Director of 5G Marketing at A10 Networks. She is responsible for developing programs and marketing material that describe business value of A10 solutions for mobile network operators and other service providers. Prior to A10 Networks, Terry has 20 years experience in the telecommunications industry, including AT&T (mobile and fixed businesses), where she developed market strategy recommendations for new business initiatives for AT&T. As a principal analyst for a syndicated market research company early in the 3G technology introduction, her 3G/4G market analysis and forecasts were published by the UMTS Forum. She also previously held positions with several start-up mobile infrastructure and software vendors, including Infoblox and Palo Alto Networks. Terry has an MBA from Arizona State University and lives in the San Francisco Bay Area. READ MORE