1 / 13

Survivability in IP-over-WDM Networks

Survivability in IP-over-WDM Networks. Introduction. Multilayer network architecture is moving into IP-optimized two-layer architecture. ․ They have same level of availability : 99.999% or 5.25 minutes of downtime per year.

aubrey-prince
Télécharger la présentation

Survivability in IP-over-WDM Networks

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Survivability in IP-over-WDM Networks

  2. Introduction • Multilayer network architecture is moving into IP-optimized two-layer architecture. ․They have same level of availability : 99.999% or 5.25 minutes of downtime per year. • Network availability is assured through a combination of equipment reliability and thevarious network survivability approaches.

  3. Introduction (contd.) • Network equipment reliability is ensured via built-in redundancy. • Survivability is the ability of the network to transfer the interrupted services onto spare network capacity to circumvent a point of failure in the network. ․Failures can involve fiber cuts and node-related failure.

  4. Importance of survivability in IP-over-WDM networks • We take an example to show the importance of survivability. ․The blocking probability can be formulated using the Erlang B loss formula : , Where W is the number of wavelengths per link. is the offered load in each node.

  5. 1 2 3 Importance of survivability in IP-over-WDM networks (contd.) - Default value : W=100 , =70 - blocking probability before failure = 0.137% increase to 140 Erlangs. - blocking probability after failure = = 51.17%

  6. IP-OVER-WDM ARCHITECTURE (contd.) • GMPLS supports two basic network architectures : overlay and peer-to-peer. • The main difference between these two models is the IP routers can see the network`s internal topology or not.

  7. IP-OVER-WDM ARCHITECTURE-- Overlay model • IP networks form the client layer where WDM networks behave as the physical transport network service provider. • There are two separate control planes : one in the core optical network and the other in the LSRs.

  8. IP-OVER-WDM ARCHITECTURE-- Overlay model (contd.) • Two alternatives to interface between IP client and WDM server ․WDM network management system (NMS) - No direct interaction between IP control and WDM control ․ User to network interface (UNI) - IP control can directly talk to WDM control through optical UNI. - Internal network-to-network interface (INNI) - External network-to-network interface (ENNI)

  9. IP-OVER-WDM ARCHITECTURE-- Overlay model (contd.)

  10. IP-OVER-WDM ARCHITECTURE-- Overlay model (contd.)

  11. IP-OVER-WDM ARCHITECTURE-- Peer to Peer model • The reachability information is shared between IP and WDM networks and a single routing protocol instances runs over both the IP and WDM networks. • The IP and WDM networks are integrated as a single network. • Tightly integration  not practical in the near term

  12. IP-OVER-WDM ARCHITECTURE-- Peer to Peer model (contd.)

More Related