Position: ZTE NGN Bearer Network Solution
ZTE offers solutions to wide-area, province-level, metropolitan, and intra-CPN bearer networks to meet the requirement of NGN network construction.
The CPN is rarely involved, so it is not discussed here. The following focuses on the solutions to the backbone and metropolitan/local NGN bearer networks.
The backbone network solution includes the construction of the nation-level or regional NGN bearer network. It involves the construction of backbone IP network. Two backbone network solutions are available for meeting the requirement of the operator:
1. If the operator has built an IP backbone network, this solution intends to connect the related NGN NEs (such as SS and TG/SG) to the IP backbone network.
2. If the operator has not built an IP backbone network or the existing IP network cannot bear NGN, a new IP bearer network needs to be built.
The figure below shows the networking of a new backbone network.
The above figure shows the networking scheme of the backbone network. The network nodes are layered according to the allocation of the network service, for example, access layer, convergence layer, and core layer. If the network scale is small, the network layers can be simplified. The NGN devices are connected through the PE router. The ZXR10 T128/T1200 offers a network link of up to 10G. The DWDM system offers the bandwidth of multiple links of 10G. The core nodes are fully interconnected or at least two links are used to connect to other nodes to ensure the high reliability of the network.
Different solutions to local networks are available according to the construction of the metropolitan area network (MAN) and the requirement of the bearer network. For the MAN that supports MPLS VPN and ensures QoS, an MPLS VPN can be separated from the MAN for NGN bearer. This networking scheme and network connection can be similar to the above backbone network solution. However, devices such as SS and TG are connected to the PEs in the MAN (instead of the backbone PEs) through the local CEs.
The following focuses on the scheme of an independent bearer network.
In the scheme of the dedicated network, an independent NGN bearer network is built to connect the related devices and ensure the QoS, reliability, availability, security, and scalability of the network.
The figure below shows the network connections.
Currently, the used core router is T128. It offers GE and OC-48 interfaces and supports the smooth upgrade of OC-192 interface. T128 supports 16 OC-48 interfaces and up to 64 GE interfaces.
The TG offers multiple uplink GE interfaces for direct connection to the core router. For a large network, the TGs can be converged and then connected to the core router. The routing module RF of the TG supports abundant interface and protocol functions to meet the flexible networking requirements.
The SS devices and SG devices (and SHLR devices) can be converged as GE devices through FE.
To ensure the security of the SS, a firewall can be placed between the convergence device and the core network for the filtering and security processing of the incoming traffic of the SS.
The IAD or AG is connected from the public network, so it is vulnerable to attack. Therefore, special processing is required for the users. From the perspective of the network connection, a large number of FE interfaces are required for the convergence of the large number of users/IADs. The users/IADs are connected through the corridor switch, converged through the MAN convergence switch, and then connected to the NGN bearer network. Besides, because of the public network environment, special security processing is required. Therefore, a firewall is required. If the NGN is borne by the dedicated network or the MPLS VPN, a private IP address is usually used. However, the IAD can be connected to the public network through a public IP address or another private IP addressing system, so the IP address translation is required. In this case, the border access control (BAC) device is required for the network isolation and the translation and processing of the IP address.
In addition, the local NGN network need be interworked with the backbone NGN network, so the connection with other networks is needed to be considered. In general, it involves the interworking with other VPNs. The simplest way is to use the NGN bearer network as CE to connect to the PE in the backbone network.
