With features such as high density, high availability, quality of service and congestion management, FocalPoint can support a wide range of telecom applications including broadband access, telecom services, aggregation and high-performance backplanes.
Broadband Access
Telecom access includes GPON, EPON, DSLAM, Cable and wireless systems which require flexible port configurations and features. Common features include the capability to interface to a wide variety of media access devices while providing high density, low-cost solutions. The figure below shows a GPON access system using a FocalPoint FM3410 on the line card and an FM3224 on the switch card. Multiple 2.5G serial links from the GPON MAC are aggregated into 10G backplane links. FocalPoint supports the VLAN tagging features required for these applications along with deep header inspection and differentiated services.
Telecom Services
Traditional Telecom Servers contain standard CPU blades running applications such as threat management, security, VPN tunneling and billing. Today’s high performance Telecom Servers employ specialized CPUs or NPUs to inspect packet headers on application blades with exception processing performed on standard CPU blades. FocalPoint can perform deep header inspection for packet pre-classification, which can off-load some of the CPU processing requirements. In addition, FocalPoint can efficiently distribute the processing load across multiple CPU blades as shown in the example below.
In this example, at the network ingress, packets will be load balanced by the FM4224 line switches to one of the application blades. These blades can then determine if the packet needs further processing by services running on other blades. If so, the packet can be routed back through the line switches for further processing. When packet processing is complete, the egress packets are load balanced across the line switches by the FM4410 device on the application blade. This in effect, load balances the packet across one of the egress LAG members back to the network. The load balancing uses a modified Persons hash function. The FM4224 line switches can also perform packet pre-classification and insert a special CPU tag that contains the classification result.
With perfect load balancing across four application blades, each blade can process the incoming packets at one quarter the line rate which greatly reduces the processing requirements and allows the use of standard CPUs or NPUs. Load balancing also provides high availability to the fabric allowing continued operation during application blade or network card failure. If a link failure is detected, software can reconfigure the LAG with the remaining members.
Aggregation
Carrier Ethernet (CE) is emerging as a standard to replace traditional SONET/SDH network backhaul equipment such as switch/routers and aggregation systems. In a CE aggregation system, multiple 1GbE links are either locally switched or aggregated through an uplink card for long-haul transport. The FM3000 Ethernet switch family can form the heart of such an aggregation system as shown in the figure below.
Here, traffic can be switched locally within the Carrier Ethernet Switch or through the FM3224 backplane devices. The FM3224 can also route data to the services cards or to the 40G uplink cards. Load balancing can be used to distribute flows across each of the four 10G ports on the uplink card. The FM3224 can assist with traffic grooming by sending VCN flow control frames to the traffic manager located in the aggregation switch and by using traffic shaping. In this way, traffic flows can be optimized for long haul transmission. Also, the FM3224 can be configured to detect OAM frames and automatically redirect them to a management CPU for processing
Backplane Fabric
Telecom backplanes lie within high bandwidth telecommunication systems and have traditionally used expensive proprietary switch fabrics due to specialized quality of service (QoS) and congestion management requirements. The FocalPoint family now offers telecom system designers the capability to design these fabrics using low-cost Ethernet switch silicon.
The FM3000 Series switch family provides advanced features such as congestion management, QoS and load balancing making it an ideal low cost solution for high bandwidth telecom backplane applications. The figure below illustrates a system using FocalPoint in a telecom backplanes including high-bandwidth switch cards and line cards. In this example, the FM3410 and the FM3212 are used as fabric interface devices on the line card while the FM3224 is used as a backplane switch device.
Here the FM3410 on the 10G line cards route the ingress traffic from the NPU across four FM3224 devices. Since the FM3224 has 24 10G XAUI interfaces, this backplane can support up to 24 10G line cards. If four of these switch cards are used in the system, an FM3212 can route ingress traffic from the NPU across eight of these devices allowing the fabric to support up to 24 20G line cards.
