Challenges and Countermeasures for IPv6 commercial deployment

The global IPv4 address is about to run out. There are two ways to address shortage: one is to introduce IPv6 to fundamentally solve the address problem, and the other is to solve the problem from the IPv4 layer. Insufficient IPv4 address space is the driving force behind migration, but the two protocols are not compatible with each other, which is the biggest reason for the inability to quickly switch. Therefore, beacon communication believes that IPv4 is evolving to IPv6, the support of all devices in the network should be gradual and gradual transition to full IPv6.

Major transition technologies introduced by IPv6

The introduction of IPv6 involves all aspects of networks and business systems. The main Evolution Routes in the industry include double stack, tunnel, and protocol translation.

Double stack

This is an end-to-end device that supports both IPv4 and IPv6 deployment configurations. It is deployed simultaneously through both IPv4 and IPv6 protocols, and IPv6 services are added without canceling IPv4, is a direct solution.

Advantage: The deployment is simple. You can upgrade the current network device to support IPv6 without changing the current network architecture.

Disadvantages: the introduction of the IPv6 plane greatly consumes Resources of the current network devices and needs to be shared with IPv4 in most key resources. In most networks, IPv4 services generally occupy more than 50% of device resources. If IPv6 is introduced, large-scale network transformation is required, which is unacceptable for both cost and investment protection.

Tunnel

Tunnel encapsulates packets to transmit packets of different protocols, without the need for a network to fully support dual-stack. There are two kinds of tunnel solutions: 6in4 and 4in6.

The 6in4 tunnel scheme keeps the current IPv4 network architecture unchanged, and supports IPv6. this scheme is common in the early introduction of IPv6. IPv6 is a small-scale deployment solution introduced in the early stage. Generally, IPv6 gateways need to be deployed at the core of the network and connect to IPv6 through tunnels to reduce network upgrade and transformation requirements.

The 4in6 tunnel solution is to build an IPv6-based network infrastructure by fully supporting IPv6 through network devices, so as to introduce the development idea of IPv6 in a large scale. For existing IPv4 services, IPv4 is carried over IPv6 to inherit and use IPv4 services. IPv4 is regarded as a service of IPv6.

Protocol translation

Protocol translation is used to solve mutual access between IPv4 and IPv6 protocols, such as NAT64 technology. Considering the complexity of Inter-protocol translation and business adaptation and compatibility issues, protocol translation technology is not currently available for commercial deployment. Terminal or service system evolution from IPv4 to IPv6 usually increases IPv6 support, rather than simply replacing it with a single IPv6 stack. Therefore, cross-access between IPv4 and IPv6 is rarely required. In addition, after IPv6 is deployed, service providers generally resolve access problems between protocols on their own. However, there is limited space for the development of solutions on the network layer, therefore, carriers generally seldom consider providing cross-access capabilities between 6 and 4 on a large scale.

Challenges of IPv6 service deployment to the operator's Network

The commercial IPv6 deployment is not an upgrade to the current simple IPv6 network. In terms of network and business development, there are still new challenges, which are embodied in the following aspects:

First, the distribution of network prefixes and the introduction of IPv4 private network addresses lead to changes in user identification and management methods. IPv6 introduces a new network prefix allocation mechanism, which allows the terminal network to be allocated an address, and more terminal access is completed within the terminal network. In terms of user management, the existing network only needs to be managed for a single user PC. The terminal network is for the access of the terminal network cloud, and is for the access management of a large number of terminals in the cloud, this is a revolutionary change in the identification of network users, requiring a great change in user operation management methods.

In addition, if a large number of IPv4 private network addresses are deployed, You need to deploy a NAT gateway for address translation. The NAT layer deployed between users will affect the NAT traversal capability of your business, thus affecting service access. In general, a user's home gateway deploys a level-1 NAT for address translation and multiplexing of multiple terminals in the terminal network. The carrier also needs to deploy level-1 NAT for address multiplexing between networks of different terminals. In this way, NAT traversal is more complex.

Second, more network resources need to be occupied, and network scalability and inheritance must be solved. As a new address family incompatible with IPv4, IPv6 is introduced to occupy network device resources dominated by IPv4. For devices running IPv4 on the network, it is not easy to perform upgrade and transformation. Generally, You need to traverse network devices that do not support IPv6 or do not support dual-stack resource capacity in a hierarchical manner to improve network scalability. However, even if the tunneling technology is used, the difference in deployment solutions will lead to a large difference between the network transformation workload and the cost. Therefore, we need to consider the existing network equipment investment to protect the existing network equipment, in addition, the inheritance and development of the scheme should be considered in introducing IPv6.

IPv6 commercial deployment solution suggestions

IPv6 introduces a multi-plane network deployment strategy based on pipelines. The backbone network layer is relatively simple and has outstanding equipment performance. It mainly uses the dual-stack dual-plane solution.

For man networks, the network architecture is complex and diverse, and there are many device models. Generally, the dual-stack multi-plane solution cannot be simply used, and the corresponding pipeline method must be used, connect incompatible networks through pipelines. Pipeline solutions are diverse, including two or three layers of pipelines and user pipelines. In special cases, pipeline splicing is also required. The specific solution needs to be selected based on the actual situation.

In the IPv6 era, broadband businesses have added a new form of user access, namely, terminal network Cloud access. This requires that multiple terminals in the terminal network be identified as one user. All terminals in the terminal cloud share the allocated network resources, such as the public network address and port range. For users who use IPv4 private network addresses, the tunnel-aware access technology is used to identify and manage users. The tunnel is isolated from other users, which saves the first-level NAT of the terminal Network Gateway, you only need to deploy NAT for the carrier network. During address translation, you can add a tunnel ID to distinguish users. This allows overlapping private network addresses to reduce the NAT level, in this way, the success rate of NAT traversal is improved. IPv6 uses the terminal identification mechanism for each user's network prefix. The new access requirements of the terminal network Cloud are actually the management of the tunnel-aware or network-aware terminal network Cloud, which requires corresponding technical innovation for the current user management and control of broadband business operations.

We recommend that you use the IPv6 centralized access network architecture in the initial phase of IPv6 introduction. The advantage of this solution is that the gateway device of the current network does not need to perform dual-stack upgrade. For users who need to provide IPv6 services, the current network gateway can wholesale them to a small number of dual-stack gateways deployed in the network. Later, when IPv6 expands to the scale stage and IPv6 Access architecture needs to be optimized to a distributed network architecture, the previously deployed IPv6 gateway device can be pushed to the network edge, as a common IPv6 gateway, this solves the problems mentioned above and protects the early device investment.

Currently, the IPRAN and OLT of beacon communication have the ability to smoothly evolve to IPv6, and the related ONU has the hardware to support IPv6. In general, we recommend that you use the management architecture of the tunnel or network-aware terminal network Cloud and a hierarchical user access architecture for IPv6 broadband services.