Participación ciudadana: ¿qué es? ¿qué tipos hay?

Artículo 6 LTAIBG. Información institucional, organizativa y de planificación

2. Participación ciudadana: ¿qué es? ¿qué tipos hay?

The definitive guide to Enterprise and Carrier Metro Ethernet applications.

Discover the latest developments in metro networking, Ethernet, and MPLS services and what they can do for your organization

Learn from the easy-to-read format that enables networking professionals of all levels to understand the concepts

Gain from the experience of industry innovator and best-selling Cisco Press author, Sam Halabi, author of Internet Routing Architectures

Metro networks will emerge as the next area of growth for the networking industry and will represent a major shift in how data services are offered to businesses and residential customers.

The metro has always been a challenging environment for delivering data services because it has been built to handle the stringent reliability and availability needs for voice. Carriers will have to go through fundamental shifts to equip the metro for next-generation data services demanded by enterprise customers and consumers. This is not only a technology shift, but also a shift in the operational and business model that will allow the incumbent carriers to transform the metro to offer enhanced data services.

Metro Ethernet from Cisco Press looks at the deployment of metro data services from a holistic view. It describes the current metro, which is based on TDM technology, and discusses the drivers and challenges carriers will face in transforming the metro to address data services.

Metro Ethernet discusses the adoption of metro Ethernet services and how that has led carriers to the delivery of metro data services. With a changing mix of transport technologies, the book then examines current and emerging trends, and delves into the role of virtual private networks (VPN), virtual private local area networks (VLAN), virtual private LAN services (VPLS), traffic engineering, and MPLS and Generalized MPLS (GMPLS).

A constraint-based routing framework can greatly reduce the level of manual configuration and intervention required to set TE policies. In practice, an operator specifies the endpoints of a traffic trunk and assigns a set of attributes to the trunk. The constraint-based routing framework is then expected to find a feasible path to satisfy the expectations. If necessary, the operator or a TE support system can then use administratively configured explicit routes to perform fine-grained optimization.

Figures 5-4a and 5-4b show two different types of routing applied to the same scenario. In Figure 5-4a, simple IGP routing is applied, and the shortest path is calculated based on the IGP metrics. A traffic trunk coming from router A is mapped to path (LSP) C-E-G-I-H. In Figure 5-4b, constraints are imposed on the routing construct. The constraint is not to use any path that has available bandwidth less than 250 Mbps. As such, the two links E-G and G-I have been removed, or pruned, from the selection algorithm, and the traffic trunk coming from router A has been mapped to path C-D-G-F-H.

Figure 5-4a. Aggregating Trunks into Tunnels

Figure 5-4b. Constraint-Based Routing

• Table of Contents

• Index

Metro Ethernet By Sam Halabi

Publisher: Cisco Press Pub Date: October 01, 2003

ISBN: 1-58705-096-X Pages: 240

The definitive guide to Enterprise and Carrier Metro Ethernet applications.

Discover the latest developments in metro networking, Ethernet, and MPLS services and what they can do for your organization

Learn from the easy-to-read format that enables networking professionals of all levels to understand the concepts

Gain from the experience of industry innovator and best-selling Cisco Press author, Sam Halabi, author of Internet Routing Architectures

Metro networks will emerge as the next area of growth for the networking industry and will represent a major shift in how data services are offered to businesses and residential customers.

Conclusion

This chapter has discussed the different parameters used for TE. Some of the concepts, such as traffic parameter attributes and policing attributes, were discussed in the context of metro deployments in Chapter 3.

The next steps for TE entail a mechanism for exchanging the traffic attributes and parameters in the network for each router to build a TE database. This database gives the routers visibility to all the network resources and attributes that can be used as input into a Constrained Shortest Path First (CSPF) algorithm. CSPF determines the path in the network based on different

constraints and attributes. Finally, a signaling protocol such as RSVP-TE is used to signal the LSP in the network based on the path determined by the CSPF. The next chapters explain the

concepts behind RSVP-TE to familiarize you with how Label Switched Path are signaled across a packet network. The book extends this concept further in Chapters 7 and 8 to discuss how MPLS signaling and routing can be extended as well to cover nonpacket networks, such as the case of an optical metro.

• Table of Contents

The definitive guide to Enterprise and Carrier Metro Ethernet applications.

Discover the latest developments in metro networking, Ethernet, and MPLS services and what they can do for your organization

Learn from the easy-to-read format that enables networking professionals of all levels to understand the concepts

Gain from the experience of industry innovator and best-selling Cisco Press author, Sam Halabi, author of Internet Routing Architectures

Metro networks will emerge as the next area of growth for the networking industry and will represent a major shift in how data services are offered to businesses and residential customers.

Chapter 6. RSVP for Traffic Engineering and Fast Reroute

This chapter covers the following topics:

Understanding RSVP-TE

Understanding MPLS Fast Reroute

Traffic engineering allows the service provider to manipulate the traffic trajectory to map traffic demand to network resources. You have seen in Chapter 5, "MPLS Traffic Engineering," that traffic engineering can be achieved by manipulating Interior Gateway Protocol (IGP) metrics or, better yet, by using a signaling protocol such as RSVP-TE. RSVP-TE offers the ability to move trunks away from the path selected by the ISP's IGP and onto a different path. This allows a network operator to route traffic around known points of congestion in the network, thereby making more efficient use of the available bandwidth. It also allows trunks to be routed across engineered paths that provide guaranteed service levels, enabling the sale of classes of service.

In metro networks, traffic engineering goes hand in hand with traffic path restoration upon failures. The behavior of a network upon failure depends on what layer the restoration methods are applied to. SONET/SDH networks, for example, can achieve restoration at Layer 1, meaning that if part of a SONET/SDH ring fails, there is always a backup TDM circuit provisioned on another fiber (unidirectional path switched ring, UPSR) or another pair of fibers (bidirectional line switched ring, BLSR). With Resilient Packet Ring (RPR), the ring is always fully utilized and a failure will cause the ring to wrap, allowing the rest of the ring to remain functional.

Restoration can also be done at Layer 2. Spanning Tree Protocol (STP) and Rapid Spanning Tree Protocol (RSTP) (802.1w) are typical methods that allow the network to converge after failure.

Layer 3 methods can also be used. Routing protocols such as Open Shortest Path First (OSPF) and Intermediate System-to-Intermediate System (IS-IS) are capable of computing multiple paths to the same destination. If the main path fails, the protocols converge to an alternate path. Mechanisms like equal-cost multipaths can also be used to allow faster convergence by having parallel active paths to the same destination.

In the use of traffic engineering and traffic restoration methods, operators look for the following:

The ability to maintain customer SLAs in case of a network failure.

The ability to achieve the most efficient use of network resources, in a way that provides good QoS that meets an SLA with their customers.

The ability to restore failure within a timeline that does not violate any SLAs they established with their customers.

Because MPLS plays a big role in delivering and scaling services in the metro, it is important to understand how it can be used to achieve TE and protection via the use of RSVP-TE. In this chapter, you see how MPLS, through the use of RSVP-TE, can be used to establish backup paths in the case of failure.

• Table of Contents

• Index

Metro Ethernet By Sam Halabi

Publisher: Cisco Press Pub Date: October 01, 2003

ISBN: 1-58705-096-X Pages: 240

The definitive guide to Enterprise and Carrier Metro Ethernet applications.

Discover the latest developments in metro networking, Ethernet, and MPLS services and what they can do for your organization

Learn from the easy-to-read format that enables networking professionals of all levels to understand the concepts

Gain from the experience of industry innovator and best-selling Cisco Press author, Sam Halabi, author of Internet Routing Architectures

Metro networks will emerge as the next area of growth for the networking industry and will represent a major shift in how data services are offered to businesses and residential customers.

In document GUÍA DE GOBIERNO ABIERTO (página 78-83)