Addressing New Working from Home Practices Through CGNAT

Adrian Taylor,  Regional VP of Sales at A10 Networks. considers how network providers can solve the increased network management challenges posed by more people working from home

The current 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 enterprises shift to online 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.  This means service providers of all types, including mobile operators, ISPs, cable operators, and CDNs are reporting increases related to the pandemic.

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.

Below are some of the different ways that traffic has changed and what the potential impacts can be for service providers:

  • Increase in daytime traffic: As workers now shift to working at home, the work-related traffic also shifts to a different geographic area. This results in an overall increase in peak “daytime” traffic from those areas and a reduction in traffic from former work locations. While this may not result in a net increase in the aggregate, it can change how local aggregation points and nodes are configured and scaled.
  • More subscriptions: Our service provider customers report that they are seeing more requests for broadband internet connections into residential areas. Mobile operators may also see an increase in mobile subscriptions as additional devices such as tablets, smartphones and mobile-enabled laptops are used for work.
  • Gaming and download increases: PlayStation traffic has tripled in one European fixed operator and one North American operator has noted software downloads have doubled.
  • Increased connection requests: Average requests per second, an indication that correlates with overall internet activity, has increased as much as 70 percent in some verticals.
  • Decreased download speed: As traffic volume increases, download speed has dropped in many countries. This often follows a stay-at-home mandate.

In our conversations with service providers through this current 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 raising 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 in price 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 (CGNAT) helps service providers meet short-term capacity requirements, extending the life of IPv4 and helping with the transition to IPv6.

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.

Utilising a Carrier Grade Networking solution similar to what we have on the market helps service providers optimise existing CGNAT infrastructure, meet short term capacity requirements, extend the life of IPv4 and transition to IPv6. We at A10 Networks have worked with several service providers during this critical time to augment their CGNAT capacity and meet the increased demand for services.