Service providers around the world agree that the Carrier Ethernet and IP/Multiprotocol Label Switching (MPLS) technology will pave the way to next-generation networks; however, there are multiple approaches to designing Carrier Ethernet networks. The objective of this paper is to provide an overview of Cisco® recommendations for designing IP Next-Generation Network (NGN) Carrier Ethernet networks.
Service providers are facing increasing challenges brought on by convergence and competition. Some of the primary challenges that must be overcome to maintain growth and profitability are:
• Accommodate exponential growth in broadband services
• Maintain competitive residential and business service offerings
• Deal with the pressures of commoditization by offering new services and Internet premium services
• Increase profitability: increase revenue while reducing total cost of ownership
• Migrate existing ATM/Frame Relay to more cost-effective Carrier Ethernet service
• Protect and grow business services in parallel with consumer services
The Cisco IP NGN Carrier Ethernet Design provides a network infrastructure that is scalable, flexible, and oriented toward new service delivery. In order to meet new business challenges, service providers must have sufficient flexibility in the network infrastructure to scale current services and quickly enable new services. The Carrier Ethernet network supports all network services equally well, including:
• Residential services
• Business services
• Mobility services
• Wholesale services
One of the main principles of Cisco IP NGN Carrier Ethernet Design is that multiple L2/L3 protocols are used to provide optimum flexibility for current and next-generation service offers. These protocols include EoMPLS, L3 PIM SSM, MPLS VPN, H-VPLS, IEEE 802.1ad, and Q-in-Q. This allows service providers to support a broad range of applications while minimizing the capital and operating expenses associated with the network infrastructure (see www.cisco.com/en/US/netsol/ns561/networking_solutions_white_papers_list.html).
It is useful to contrast this flexible approach to network design with a more rigid approach (advocated by some network designers) that proposes that H-VPLS be the sole technology used in the access and aggregation network and L3 IP routing be restricted to the core network. While H-VPLS is a good technology for some services and applications, it is not the best approach for all applications and service providers. For example, H-VPLS is not well suited to distributing broadcast video because it requires the use of proprietary multicast technology which is not scalable. In contrast IP NGN advocates PIM SSM, a proven, scalable, IETF standards based approach to delivering IP multicast traffic. Similarly, in many cases, L3 MPLS VPNs provide the best approach to creating a wholesale service due to the ubiquity of MPLS VPNs in SP networks. There are also many other cases where H-VPLS is force fit to solve a problem that is better solved at Layer 3. For this reason Cisco advocates a more flexible approach to Carrier Ethernet design that minimizes the total cost of ownership of the access and aggregation network while supporting a broad range of applications and services.
The IP NGN Carrier Ethernet Design is the most scalable approach to delivering residential IPTV because it uses standards based IP multicast (PIM) to deliver broadcast video over the IP network. PIM is the only IP multicast protocol that has been proven to operate reliably on a large scale. Cisco's PIM has been optimized for IPTV providing fast routing convergence and fast channel change necessary for production IPTV.
The IP NGN Carrier Ethernet Design is used in combination with Cisco's Service Exchange Framework to provide a robust and flexible approach to offering a wide variety of residential, business, mobile, and wholesale services. The following sections of this paper present an overview of network services evolution, the principles of the IP NGN Carrier Ethernet Design, some of the specifics around video services, and a discussion of the Service Exchange Framework.
Network Services Evolution
A service provider's agility and flexibility in service delivery is critical to its long term success. Most large service providers need the flexibility to offer residential, business, mobile, and wholesale services. This section of the paper gives an overview of current service requirements and provides a roadmap to the future.
Residential Services
In order to maximize service revenues and minimize subscriber churn, a common service provider strategy is to offer a complete set of bundled triple play services to residential subscribers that include:
• Voice
• High-speed Internet
• Broadcast TV
• Video on demand (VoD)
Bundled services are offered at attractive price points so as to encourage subscribers to purchase all services from a single provider. Multimedia service integration is an important factor for IP convergence in the network. Voice services are delivered using VoIP and video services are delivered using IPTV and IP VoD. In order to accommodate triple play, it is vital that the network be able to scale to tens and even hundreds of gigabits/sec.1 Large traffic growth is expected to be encouraged by growth in VoD and high-definition (HD) content delivered over both IPTV multicast and VoD unicast connections.
Business Services
Business subscribers are an important segment of many service providers' customer base. The main business services that must be provided by the network today are:
• MPLS VPN
• Carrier Ethernet
• Managed services
Furthermore, Carrier Ethernet services have been defined by the Metro Ethernet Forum to include both E-Line and E-LAN service types, which are defined below:
• E-Line: An Ethernet service type that is based on a Point-to-Point Ethernet Virtual Connection. Two E-Line services are defined:
– EPL (Ethernet Private Line): This is a very simple point-to-point service characterized by low Frame Delay, Frame Delay Variation, and Frame Loss Ratio. No service multiplexing is allowed, and other than a Committed Information Rate (CIR) no CoS (Bandwidth Profiling) is allowed.
– EVPL (Ethernet Virtual Private Line): This is a point-to-point service wherein service multiplexing (more than one Ethernet Virtual Circuit) is allowed. The individual Ethernet Virtual Circuits can be defined with the rich set of Bandwidth Profile and Layer 2 Control Protocol Processing methods defined by the Metro Ethernet Forum.
• E-LAN: An Ethernet service type that is based on a Multipoint-to-Multipoint Ethernet Virtual Connection. Service multiplexing - more than one Ethernet Virtual Circuit at the same UNI - is permitted, as is the rich set of performance assurances defined by the MEF such as CIR with an associated Committed Burst Size (CBS) and Excess Information Rate (EIR).
Business services typically provide secure bandwidth with dedicated QoS. This can be done either at Layer 3 using an MPLS VPN2 or directly over Ethernet using a Layer 2 Carrier Ethernet service.3 Additionally, many businesses favor outsourcing management of WAN routers and firewalls to the service provider (see www.cisco.com/en/US/netsol/ns546/networking_solutions_solution_category.html). The Carrier Ethernet network must be able to offer all these services with secure and dedicated bandwidth.
Mobility Services
Mobile networks also are moving to broadband IP infrastructure. As service providers deploy 3G, WiMax, Wi-Fi Hotspots, and Hotzones, the aggregation network must scale to support backhaul of broadband wireless data. Carrier Ethernet is the preferred technology for broadband wireless backhaul.
Wholesale Services
Many service providers offer both residential and business wholesale services to other retail service providers. Retail service providers typically require interconnectivity to their subscribers over a tunnel or VPN. For example, a wholesale service provider might provide DSL infrastructure for a retail service provider's Internet customers. The wholesale provider might connect each subscriber to the retail provider using an L2TP backhaul tunnel across the Internet. The customer relationship is with the retail service provider, but transport is provided by the wholesale provider.
Service Evolution
In the future we expect to see continued convergence across residential, business, and mobile services. Today most customers have separate mobile and landline phone service; however, in the future many service providers will offer a converged fixed-mobile service. Customers will subscribe to a single phone service that will be delivered either to their cell phone, landline, or softphone (on their PC) depending on their location and their preferences. Similarly, service providers will offer converged video services that will be delivered to an HDTV, PC, cell phone, or wireless PDA based on customer preference. The overall industry trend will be any service, any screen, with fully personalized services and integrated multimedia applications for both business and entertainment.
Figure 1. Service Evolution
IP NGN Carrier Ethernet Design
The IP NGN Carrier Ethernet Design is the physical instantiation of an IP NGN architecture in an actual network design (for more information on IP NGN, see www.cisco.com/en/US/netsol/ns537/networking_solutions_solution_category.html). It uses key elements of the IP NGN architecture to enable a best-in-class implementation for Carrier Ethernet. Service Exchange Framework (SEF) components also are incorporated into this design. The objective of this design is to provide a flexible, scalable, and reliable network to meet current and future network service requirements. The Carrier Ethernet network is divided into a hierarchy of elements that are depicted Figure 2. These elements are:
• Access: Provide access to residential and business customers over DSL, fiber, cable, or wireless.
• Edge Aggregation: Aggregate the access network across a Carrier Ethernet network and providing interconnectivity to the IP/MPLS edge and IP/MPLS core.
• Intelligent Service Edge: Interface services with the IP/MPLS Core - This is the Provider Edge for both residential and business subscriber services.
• IP/MPLS Core: Provide scalable IP/MPLS routing in the core network.
• Policy/Service Layer: Provide broadband policy management to control service delivery - a key component of the Service Exchange Framework.
Figure 2. IP NGN Carrier Ethernet Design
Access
The access component of the network provides physical wired or wireless access to subscribers. The Carrier Ethernet network must provide transport for all types of access networks and devices, including SONET and SDH MSPP networks, cable, DSL, PON, E-FTTx, WiMax, 3G Wireless, and Wi-Fi hotspot and hotzone networks. Furthermore, services must be crafted based on the type of customer and the type of access network.
Edge Aggregation
The Edge Aggregation network is the heart of the IP NGN Carrier Ethernet Design. It provides Ethernet transport services for all types of services, customers, and access technologies. The Cisco approach to Carrier Ethernet Design allows all services to be optimized independently. This is enabled by support of multiple L2/L3 protocols in the Ethernet transport network. These protocols include:
• Layer 3 routing with PIM SSM Multicast
• Layer 3 MPLS VPN and multicast VPN (RFC 2547bis)
• H-VPLS
• EoMPLS (Pseudo Wires)
• IEEE 802.1q, 802.1ad, 802.1ah
One reason that it is critical to support multiple protocols in the aggregation network is that different customers, services, and applications have different requirements that can not be addressed by a single, one size fits all approach to network design (such as H-VPLS only). Another reason that multiple protocols must be supported is that service providers have unique approaches to network architecture and design. The flexibility provided by wide Cisco support of L2/L3 protocols in the aggregation network allows service providers to design the network according to their own design guidelines and architecture, not design guidelines mandated by the vendor.
Any of the protocols specified above can be used for any service with the exception of residential video broadcast service. Because video broadcast service requires IP multicast, it is necessary that residential video broadcast use L3 IP multicast with PIM SSM over MPLS with Fast ReRoute (FRR). This provides a highly scalable and reliable architecture for broadcast TV service. Similarly, wholesale residential broadcast video service should use L3 multicast over an MPLS VPN (RFC 2547bis) to provide both scalability and logical separation from other retail networks and customers.
While service providers are free to choose transport protocols that best suit their network architecture and applications, Table 1 presents a summary of Cisco recommended protocols for different network services. In general, EoMPLS Pseudo Wire transport is recommended for many services that require Ethernet transport with QoS. Since EoMPLS uses IETF Pseudo Wire standards, it is scalable, and it provides QoS.
Table 1. Recommended Protocols for Different Services
Service
Recommended Transport Protocols
Transport Function
Residential High-Speed Internet
EoMPLS or IEEE 802.1ad
Backhaul Internet traffic from the Access Network to the Broadband Remote Access Router for AAA and service control. Provide QoS, tiered, quota based, and usage based Internet access.
Residential VoIP
EoMPLS or L3 IP Routing over MPLS FRR
Connect signaling traffic to Softswitch and RTP traffic to Internet or Core IP network. Provide QoS.
Residential IPTV
L3 PIM SSM over MPLS FRR
Broadcast TV service with massive scalability, fast recovery from failures, and excellent Quality of Experience (QoE).
Residential Video on Demand
L3 IP Routing over MPLS FRR
Video-on-Demand service with massive scalability, fast recovery from failures, and excellent Quality of Experience (QoE).
Business Ethernet Private Line (EPL)
EoMPLS or IEEE 802.1ad
Transport of Ethernet circuit at full data rate with no statistical multiplexing. This requires QoS.
Business Ethernet Virtual Private Line (EVPL)
EoMPLS or IEEE 802.1ad
Transport of Ethernet virtual circuit with CIR/EIR and statistical multiplexing gain.
Business MPLS VPN
MPLS or IEEE 802.1ad
Transport of subscriber Ethernet virtual circuit to MSE PE router that is the provider edge of the MPLS VPN service. CIR/EIR guarantees bandwidth.
Business E-LAN
H-VPLS or IEEE 802.1ad
Multipoint virtual LAN service for business customers. CIR/EIR guarantees bandwidth.
Mobile Backhaul
EoMPLS or IEEE 802.1ad
Pseudo Wire backhaul for 3G, WiMax, and Wi-Fi networks.
Wholesale Residential High-Speed Internet
EoMPLS or IEEE 802.1ad
Pseudo Wire backhaul from the access network to the retail service provider.
Wholesale IPTV and VoD
RFC 2547bis MPLS VPN with multicast
Private IP network with multicast that interconnects the retail service provider with the access network.
Wholesale Business Services
EoMPLS or IEEE 802.1ad
Provide transport from the business customer to the retail service provider with EIR/CIR bandwidth guaranties.
Intelligent Service Edge
The IP/MPLS Edge is where many network services are terminated and managed. There are three main functions performed at the IP/MPLS Edge:
• Broadband Remote Access Router
• Multiservice Provider Edge Router (MSE PE)
• Deep Packet Inspection (DPI)
Broadband Remote Access Router
The Broadband Remote Access Router is primarily responsible for residential high-speed Internet (HSI) subscriber management and wholesale services. Subscriber traffic is transported across the Ethernet access and aggregation network and terminated on the Broadband Remote Access Router. Functions provided by the Broadband Remote Access Router include:
• Termination of residential HSI services
• Terminate, route, or tunnel wholesale HSI using L2TP or MPLS VPN
• Radius, AAA, and dynamic subscriber and policy control for PPPoE and IPoE sessions
MSE PE
Business traffic is transported across the Carrier Ethernet network to the MSE PE, where MPLS VPN services as well as existing Frame Relay and ATM services are terminated. The MSE PE provides virtual IP routing (RFC 2547bis) functionality as well as Frame Relay and ATM to MPLS interworking functionality.
DPI
The Deep Packet Inspection function implements application layer traffic management and premium Internet service delivery control. It carries out traffic policing and monitoring (for example, rate limiting of P2P traffic) and also is an integral part of the Service Exchange Framework.
IP/MPLS Core
The IP/MPLS Core is the backbone network that interconnects all Ethernet aggregation networks. The core network is based on the highly scalable CRS-1 router. All packet forwarding in the core network should be carried out by scalable Layer 3 IP/MPLS routers.
Policy/Service Layer
The policy service layer is where management and instantiation of network services are controlled. It is fully defined by the Service Exchange Framework, which is more fully described in a separate section of this paper.
Video Services
One of the most challenging and important services carried over the IP NGN Carrier Ethernet network is video. Video services consist of broadcast IPTV and Video-on-Demand. Both these services can carry either Standard Definition (SD) or High-Definition (HD) content. Video is important because it can contribute large revenues to a service provider. It is challenging because of the quantity of stream-oriented traffic generated. Unlike Internet traffic, video traffic is intolerant of delays, packet loss, and network outages. Packet loss ratios that are greater then 10-6 and outages greater than 2-3 seconds can seriously compromise video quality.
As part of the IP NGN Carrier Ethernet Design, Cisco has a comprehensive solution for delivering high-quality and high-availability IPTV and VoD. This solution is described more fully in another white paper entitled "Delivering Video Quality in Your IPTV Deployment."4 The main strengths of Cisco's video delivery solution are:
• Layer 3 video distribution with enhanced PIM SSM and IGMP provides consistent subsecond convergence and recovery from all types of failure scenarios. PIM is a highly scalable and robust protocol that is proven in large multicast networks.
• Both IPTV and Video-on-Demand are controlled by a robust Cisco Integrated Video Admission Control solution that monitors network topology changes and traffic and provides throttling of video admission if necessary. This prevents network meltdowns that could be caused by video exceeding network capacity.
• The Cisco solution minimizes channel change time by reducing or eliminating the main sources of channel change delay.
Service Exchange Framework
As network services make the transition from triple play to any-service-any-screen over converged wireline and mobile networks, service policy management and control become essential components of the network infrastructure. Furthermore, services must be device and access agnostic. To achieve true access independence, network operators must achieve better understanding, visibility, and control of their networks by answering such questions as who their subscribers are and what services they are authorized to use.
Service providers must be able to dynamically control network access, determine the identity of subscribers, and gain a better understanding of services they use "on-the-fly." With greater granular visibility and control, service providers can achieve new levels of insight into customer activity while simultaneously delivering differentiated and value-added new services, more securely and more profitably.
Some of the key benefits of the Service Exchange Framework (SEF) are:
• Managing P2P applications
• Empowering subscribers by allowing them to personalize services
• Helping ensure high-quality video delivery by implementing video admission control
• Enabling new business models by allowing subscribers to create new premium service offerings
SEF is composed of two primary layers: the policy management layer and the packet forwarding and processing layer. The policy management layer configures services based on subscriber profiles and service definitions and controls the components in the packet forwarding layer to implement these services. The policy management layer is implemented using the Cisco Broadband Policy Manager (BPM), and the packet forwarding layer is implemented using:
• Service Control Engine (SCE): A DPI engine providing traffic shaping, monitoring, and service control
• Integrated Services Gateway (ISG): A software component residing on routers and switches that enables advanced services
SEF is an essential component of the IP NGN Carrier Ethernet Design, enabling next-generation services. For more information on SEF, see www.cisco.com/en/US/products/ps7045/index.html.
Conclusion
The IP NGN Carrier Ethernet Design is a network solution that enables service providers to build an infrastructure that has the necessary flexibility to support current and next-generation services, and the capability to scale to support increasing network traffic, and is a highly reliable infrastructure providing both QoS and QoE to end users. It is a converged Ethernet/IP network providing residential, business, mobile backhaul, and wholesale services. Many L2 and L3 protocols are supported, allowing service provider engineers and architects to select the optimum network design for the specific services, applications, and customers they are serving. IP NGN also provides an optimal IPTV and VoD solution for service providers. IP L3 routing, using PIM SSM, is a proven, highly scalable solution for multicast delivery of IPTV. Furthermore, the video solution minimizes channel change time by eliminating and/or minimizing sources of delay. In combination with the Service Exchange Framework, the IP NGN Carrier Ethernet Design gives service providers the tools they need to grow revenues and create high-margin services for the future.
Appendix
Cisco Products
Table 2 matches Cisco products with the elements of the IP NGN Carrier Ethernet Design.
Table 2. Cisco Products That Can Be Used in Each Element of the NGN Carrier Ethernet Design
Elements of Carrier Ethernet Design
Cisco Products
Access
• Cisco ME 3400 Series Ethernet Access Switches
• Cisco Catalyst® 3750 Metro Series Switches
• Cisco Catalyst 4500 Series Switches
• Cisco Catalyst 6500 Series Switches
• Cisco ME 6524 Ethernet Switch
Edge Aggregation
• Cisco 7600 Series Routers
Intelligent Service Edge
• Cisco 10000 Series Routers (Broadband Remote Access Router)
• Cisco 7200 Series Routers (Broadband Remote Access Router)
• Cisco 7300 Series Routers (Broadband Remote Access Router)
• Cisco 12000 Series Routers (MSE PE)
• SCE 1010 (DPI)
• SCE 2020 (DPI)
IP/MPLS Core
• Cisco CRS-1 Carrier Routing System (CRS-1)
Service Exchange Framework
• Broadband Policy Manager
• SCE 1010
• SCE 2020
• ISG (Software for routers)
Glossary
Acronym
Definition
AAA
In computer security, AAA stands for "authentication, authorization, and accounting".
Authentication refers to the confirmation that a user who is requesting services is a valid user of the network services requested.
Authorization refers to the granting of specific types of service (including "no service") to a user, based on their authentication, what services they are requesting, and the current system state.
Accounting refers to the tracking of the consumption of network resources by users. This information may be used for management, planning, billing, or other purposes.
CIR
Committed Information Rate or CIR in a Carrier Ethernet network is the average bandwidth for an Ethernet Virtual Circuit guaranteed by a service provider.
EIR
Excess Information Rate or EIR is the maximum rate that a Carrier Ethernet subscriber can burst to assuming that on average they do not exceed the CIR.
EoMPLS
Transport of native Ethernet over an MPLS Pseudo Wire (PW).
H-VPLS
Virtual private LAN service (VPLS) is a way to provide Ethernet based multipoint to multipoint communication over IP/MPLS networks. It allows geographically dispersed sites to share an Ethernetbroadcast domain by connecting sites through pseudo-wires. The technologies that can be used as pseudo-wire can be Ethernet over MPLS, L2TPv3 or even GRE. There are two IETF standards describing VPLS establishment, currently in Internet Draft status, but expected to be published as RFCs soon. VPLS requires a full mesh of LSPs which has the n2 scaling problem. H-VPLS helps solve this problem by dividing the virtual LAN into separate hierarchies.
IEEE 802.1ad
IEEE 802.1ad (Provider Bridges) is an amendment to IEEE standard IEEE 802.1Q-1998, intended to develop an architecture and bridge protocols to provide separate instances of the MAC services to multiple independent users of a Bridged Local Area Network in a manner that does not require cooperation among the users, and requires a minimum of cooperation between the users and the provider of the MAC service. This is a standard version of the Q-in-Q protocol used by Cisco for Carrier Ethernet Service.
IEEE 802.1ah
Provider Backbone Bridges (PBB) is being formalized by IEEE 802.1ah standards. It allows for layering the Ethernet network into customer and provider domains with complete isolation among their MAC addresses. It defines a B-DA and B-SA to indicate the backbone source and destination address. It also defines B-VID (backbone VLAN ID) and I-SID (Service Instance VLAN ID).
IEEE 802.1q
IEEE 802.1Q was a project in the IEEE 802 standards process to develop a mechanism to allow multiple bridged networks to transparently share the same physical network link without leakage of information between networks (i.e., trunking). IEEE 802.1Q is also the name of the standard issued by this process, and in common usage the name of the encapsulation protocol used to implement this mechanism over Ethernet networks. IEEE 802.1Q also defines the meaning of a virtual LAN or VLAN with respect to the specific conceptual model underpinning bridging at the MAC layer and to the IEEE 802.1Dspanning tree protocol. This protocol allows for individual VLANs to communicate with one another with the use of a Layer 3 (network) router.
IPoE
IP over Ethernet is used in DSL and PON access networks in place of PPPoE.
L2
Layer 2 of the protocol stack. This typically refers to the set of Ethernet protocols that operate below the IP layer of the protocol stack.
Layer 3 of the OSI protocol stack. This refers to the IP protocol used for routing in the Internet.
MPLS VPN
An L3 virtual IP network specified by RFC 2547bis. It used a combination of BGP routing and MPLS forwarding to create a virtual IP network on top of a service provider's physical IP network. MPLS VPN services are replacing Frame Relay and ATM services.
PIM SSM
A family of multicastrouting protocols that can provide one-to-many and many-to-many distribution of data over the Internet. The "protocol-independent" part refers to the fact that PIM does not include its own topology discovery mechanism, but instead uses routing information supplied by other traditional routing protocols such as Border Gateway Protocol (BGP). PIM Source Specific Multicast (PIM-SSM) builds trees that are rooted in just one source, offering a more secure and scalable model for a limited amount of applications (mostly broadcasting of content). In SSM, an IP datagram is transmitted by a source S to an SSM destination address G, and receivers can receive this datagram by subscribing to channel (S,G). See informational RFC 3569.
PPPoE
PPPoE, Point-to-Point Protocol over Ethernet, is a network protocol for encapsulating PPP frames in Ethernet frames. It is used mainly with ADSL services. It offers standard PPP features such as authentication, encryption, and compression.
Pseudo Wire (PW)
Emulation of a native service over a Packet Switched Network (PSN). The native service may be ATM, Frame Relay, Ethernet, low-rate TDM, or SONET/SDH, while the PSN may be MPLS, IP (either IPv4 or IPv6), or L2TPv3. The first PW specifications were the Martini draft for ATM PWs, and the TDMoIP draft for transport of E1/T1 over IP. In 2001, the IETF set up the PWE3 working group, which was chartered to develop an architecture for service provider edge-to-edge PWs, and service-specific documents detailing the encapsulation techniques. Other standardization forums, including the ITU and the MFA Forum, are also active in producing standards and implementation agreements for PWs.
Q-in-Q
An enhancement of IEEE 802.1q that allows service providers to create Carrier Ethernet VLANs that will preserve the IEEE 802.1q headers used in the internal enterprise VLAN.
QoE
Quality of Experience. This is a subjective term that represents the quality of experience in video or voice delivery. For example, if the TV picture is distorted or if the frame freezes this represents a poor level of QoE.
QoS
Quality of Service (QoS) refers to control mechanisms that can provide different priority to different users or data flows, or guarantee a certain level of performance to a data flow in accordance with requests from the application program.
RTP
The Real-time Transport Protocol (or RTP) defines a standardized packet format for delivering audio and video over the Internet. It was developed by the Audio-Video Transport Working Group of the IETF and first published in 1996 as RFC 1889, which was made obsolete in 2003 by RFC 3550.
WiMAX is defined as Worldwide Interoperability for Microwave Access by the WiMAX Forum, formed in June 2001 to promote conformance and interoperability of the IEEE 802.16 standard, officially known as WirelessMAN. The Forum describes WiMAX as "a standards-based technology enabling the delivery of last mile wireless broadband access as an alternative to cable and DSL."
3G
3G (or 3-G) is short for third-generation technology. It is used in the context of mobile phone standards. The services associated with 3G provide the ability to transfer simultaneously both voice data (a telephone call) and non-voice data (such as downloadinginformation, exchanging email, and instant messaging). 3G basestations require Ethernet backhaul.
2MPLS VPN service is a standard specified by RFC 2547bis. It allows service providers to offer a virtual IP network to customers that rides on top of their MPLS network infrastructure. Customers can connect to the MPLS VPN using a variety of access technologies, including DSL, Frame Relay, T1, and Ethernet.
