Comprehensive Exploration of IPv6 broadband access network deployment Solutions

There are many things worth learning about IPv6 broadband access network. Here we mainly introduce the IPv6 broadband access network deployment solution. Considering the development trend of the Next Generation Internet, in the future, IPv6 broadband access networks should be able to allocate a static IPv6 address segment to each user. Therefore, we need to consider the introduction of some new technologies. This article describes four typical IPv6-based broadband access network deployment solutions. New IPv6 features and advantages:

1. Simplified data packet format

IPv6 simplifies the IP packet header format. IPv6 data headers only contain 8 fields, while IPv4 contains 12 fields. This simplified package structure helps to compensate for the bandwidth overhead caused by the increase of IPv6 address length.

2. expanded Address Space

The IPv4 address is only 32 bits in length and can theoretically provide 4.3 billion IP addresses. IPv6 expands the number of IP addresses from 32 to 128. Theoretically, it can provide up to 2 IPv6 addresses to the power of 128, which can completely solve the problem of insufficient IPv4 address space.

3. Automatic Configuration

One of the basic features of IPv6 is its support for stateless and stateful address automatic configuration.

4. Service Quality

From the Protocol perspective, IPv6 provides different levels of services for different streams. IPv6's service quality improvement is also reflected in its support for "always-on-line" connections, service interruption prevention, and network performance improvement.

5. Security

IPSecIP Security) is optional in IPv4 and mandatory in IPv6. IPv6 is consistent with the IPSec mechanism and service.

Deployment of IPv6 Broadband Access Networks

Existing IPv4 access network users only obtain a dynamically assigned IP address when accessing the Internet. Considering the development trend of the Next Generation Internet, in the future, IPv6 broadband access networks should be able to allocate a static (or dynamic) IPv6 address segment to each user. Therefore, we need to consider the introduction of some new technologies. The following describes several typical deployment implementation solutions.

Solution 1: LAN/ATM route access

This scheme requires an ADSLModemADSL router that integrates the routing function ). BAS is deployed on the carrier's backbone network and is responsible for IPv4 and IPv6 broadband access networks. Create an ATMPVC between the BAS and the ADSL Router. Both IPv4 and IPv6 can be transmitted through the same PVC in RFC1483/2684 mode. In this way, the configuration of the ADSL Router is static, that is, the IPv4 public network address and IPv6 prefix are defined in the configuration file. The advantage of this access scheme is that it directly provides an ATM connection between the operator and the user to facilitate the development of value-added services such as VPN and QoS. At the same time, the static configuration of the ADSL Router, the carrier does not need to establish PPP sessions and deploy dedicated Address Allocation servers.

Solution 2: PPP/ATM route access

In this solution, the connection between BAS and ADSLModem is dynamically established through PPP. IPv4 and IPv6 connection attributes are stored in a centralized Radius database. PPPv4 sessions (IPCP) and PPPv6 sessions (IPv6CP) can share a PPP connection. After receiving the connection request, BAS queries the Radius server to obtain the corresponding connection attribute, and then establishes a session with the ADSL Router. IPv6 Configuration parameters are transmitted through DHCPv6. BAS serves as the server of DHCPv6 and the ADSL Router serves as the client. The prefix Assignment Mechanism Based on DHCPv6 is used to assign IPv6 address prefixes to users, so as to realize automatic address configuration. The advantage of this solution lies in the strong scalability of centralized user management and automatic configuration. In addition, because two Radius servers are used to process IPv4 and IPv6 attributes separately, you can deploy IPv6 broadband access networks without making any changes to the existing IPv4 access network structure.

Solution 3: LAN and PPP/ATM Hybrid Bridge access

IPv4 access adopts the traditional access mode: IPv4 user terminals (PCS) send their identification information to BAS through the PPPoE connection between the Modem and BAS, BAS forwards the user identification information to the Radiusv4 server for authentication. After successful authentication, the Radiusv4 server returns the PPP connection parameters and terminal configuration information to the BAS. The BAS forwards the information to the user, and the user terminal uses the information for corresponding configuration, to establish an IPv4 access connection. In the 1483/2684 bridging mode, you can obtain IPv6-related configuration information from the Radiusv6 server through a similar process, and then establish an IPv6 Access connection. In this way, IPv4 and IPv6 connections can share an ATMPVC connection. This access method has three advantages: the existing IPv4 access network structure can provide IPv6 Access Services without changes; for pure IPv6 terminals, you can assign a globally unique IPv6 address visible to the operator, it facilitates the development of new IPv6 services. This method can also provide users with IPv4 and IPv6 broadband access network services, so that operators can gradually smoothly transition to IPv6.

Solution 4: PPP/L2TP route access

This method establishes an L2TP tunnel between the BAS and the carrier's backbone routers to host IPv4PPP and IPv6PPP sessions. The BAS act as the L2TP Access Concentrator (L2TPAccessConcentrator, LAC) and the backbone router acts as the L2TP network server (L2TPNetworkServer, LNS ). This IPv6 broadband access method is particularly suitable for operators to provide value-added services for enterprise users.