1. ===!"§ Deutsche Telekom Innovation Center Deutsche Telekom AG Innovation Center Scenarios for L1VPNs September 26, 2005 Discussion paper for NOBEL Paris Meeting September 2005 Georg Lehr, T-Systems SSC ENPS PCT 52gl

2. Page 1 ===!"§ Deutsche Telekom Innovation Center Outline L1VPN – A simple approach, benefits for customers and providers Scenarios for Takeda framework Assessment of L1 VPN Discussion of broadcaster’s scenario

3. Page 2 ===!"§ Deutsche Telekom Innovation Center Simple view Definition of Virtual Private network: — Network can be operated as if it was fully owned by the customer. e.g. private address plan full management visibility and management capabilities on own resources no impact of “outer world” (security/privacy; closed user group …) — This ownership is only virtual, as it is partly shared with other customers Sharing can be on: — data plane level : (transmission resources such as subnetworks, nodes, or links are shared) — level of control : control plane hard and software; but: information exchanged by routing protocols is dedicated (membership, customer routing info and provider routing info is only exchanged between the PE and CE members of the VPN). — level of management and operation: management infrastructure is shared, operational labour and expertise is shared. but: management information is dedicated (customer’s management view and capabilities are restricted to VPN resources) … on L1VPNs

4. Page 3 ===!"§ Deutsche Telekom Innovation Center Simple view Sharing has two aspects: — economies of scale regarding resources and operation. — economies of expertise These aspects enable — Attractive costs for production — Outsourcing and other value added services Additional effort for implementation — limitation of distribution of information within VPN in CP via routing protocols in MP via access rights on resources both: measures to guarantee security — limitation of access to resources in CP policing functions (CAC-functions) in MP see above both: measures to guarantee security Competition, if services are comparable and provided via standardized interfaces — data level is standardized — CP is going to be standardized — MP interfaces: chance to provide proprietary solution with high customer benefit (e.g. in systems solution business). … on L1VPNs

5. Page 4 ===!"§ Deutsche Telekom Innovation Center Customer benefits Customer can outsource operation of an Layer 1 Network. This takes the burden from the customer: — to perform the network management tasks — to provide a 7/24 service / helpdesk — to train and employ people with a very specialized operational experience (with skills often far away from the core business). — to operate a complicated network management infrastructure Sharing of resources: — customer can afford small network by sharing the full cost of ownership with other customers. The smaller the network is, the better the economy of scale (for equipment and labour). … of L1VPNs

6. Page 5 ===!"§ Deutsche Telekom Innovation Center Customer benefits (ctd.) Customer does not have to care about technical details, but can rather rely on parameters guaranteed in SLAs; the provider has to take care how availability goals can be met - also for different routes: — availability — latency — SNR for optical networks — reachability for dynamic services Customer can integrate networks from different providers with an optimized cost / quality relationship. — different layers — different regions “in parallel” (to implement diversity) in sequence (to build a global network, if no global provider is available or is too expensive) … of L1VPNs

7. Page 6 ===!"§ Deutsche Telekom Innovation Center Provider benefits Provider can sell a value added service to the customer, not only connectivity but rather: — supervised connectivity — with guaranteed availability — guaranteed reachability (in terms of busy hour call attempts) — guaranteed latency — Management capabilities such as Detailed management access from simple web applications (visibility, fault, performance …) Advanced billing functions (e.g. interfaces to SAP …) Other integration functions (e.g. integration with customer’s order management, SAP …) Helpdesk and 7/24 h support Provider can make better use of spare resources Provider can share the effort for expensive lower layer network management integration; customer needs only a simple browser. … of L1VPNs

8. Page 7 ===!"§ Deutsche Telekom Innovation Center ITU-T  Takeda draft The ITU-T provided in the Y series some generic views on L1VPNs. This work has been used as starting point for discussion in IETF. draft-takeda-l1vpn-framework-04.txt: Tomonori Takeda (Editor): “Framework and Requirements for Layer 1 Virtual Private Networks”; June 2005

9. Page 8 ===!"§ Deutsche Telekom Innovation Center Service requirements and service models Info exchange at CE-PE interface Data plane shared Data plane dedicated Signaling Overlay Signaling + Membership information Overlay Extension Signaling + Membership information + Customer network routing information Virtual Node Signaling + Membership information + Customer network routing information + Provider network routing information Not applicable Virtual Link Per-VPN Peer Possible combinations of info exchange and sharing draft-takeda-l1vpn-framework-04.txt

10. Page 9 ===!"§ Deutsche Telekom Innovation Center Service requirements and service models n The table provides a mapping between service models — overlay — overlay extension, — virtual node, — virtual link, — per VPN peer to functionality provided by the network — signaling plus — different levels of information transfer n The table distinguishes further between shared and dedicated dataplanes. Significance of the table

11. Page 10 ===!"§ Deutsche Telekom Innovation Center Taxonomy of L1VPN Service Models Management based service model Control based service model Signaling based service model (Overlay service model)* Signaling based service model (Overlay service model)* Signaling and routing service model Virtual link service model Per VPN peer service model Type of the customer interface Type of information exchanged Type of routing information exchanged NNI (Peer) type of interface UNI (Overlay) type of interface Draft-takeda-l1vpn-framework-03.txt Virtual node service model Overlay Overlay (extension) Type of membership information exchanged Service models are classified by semantics of information exchanged over the customer interface * [GVPN] calls this service GVPW (generalized virtual private wire service)

12. Page 11 ===!"§ Deutsche Telekom Innovation Center Information exchange at the PE-CE Interface Can be used to classify the scenarios PE CE link CPI PPI CE PE link PPI C PI GMPLS enabled BB Signaling Membership information : {(CPI n,PPI n, ); ….}; (CPI are private, PPI public addresses) local (same PE) and remote (other PEs) distribution restricted to the specific VPN Customer network routing information Provider network routing information Provider Network Customer Network Customer Network

13. Page 12 ===!"§ Deutsche Telekom Innovation Center Shared data plane vs. dedicated data plane n Sharing the data plane enables the network operator to better utilize the resources. He can share this advantage with the customer. n Sharing of the resources has impact on: — resource availability — security n Sharing of resources implies, that the customer has no influence on the routing process (hence in a a shared data plane, no provider routing info is exchanged, see table. Therefore, sharing has also impact on: — latency — availability of the connection, (as the MTBF depends on the length of the connection): — performance (in the case of transparent optical L1VPNs) n On the other hand, availability of resources can be guaranteed only on the level of probabilities. This probability is agreed upon in the SLA (e.g. as BHCA = busy hour call attempts). Penalties are fixed for the case when the statistical value can not be met by the operator in an agreed time interval. n The network operator must try to meet the SLA by providing a reasonable basis of resources. The planning process must take into account a predicted user behaviour, the cost for resources and penalties. Can be used to classify the scenarios

14. Page 13 ===!"§ Deutsche Telekom Innovation Center Scenario: Overlay Model UNI Customer 2 Customer 1 UNI Customer 2 UNI Customer 1 is connected to can connect to has visibility UNI-C based VPN

15. Page 14 ===!"§ Deutsche Telekom Innovation Center Scenario: Overlay Model Restriction of Management Visibility: — management view only on resources that have been ordered /are under service contract Restriction of reachability: — only nodes within the user group (VPN-internal) can call each other — only calls from nodes within the user group (VPN-internal) are accepted or: - outgoing access to VPN-external destinations - incoming access from VPN-external sources Generally — One contract, one Service Level Specification, one bill,... Management requirements / CP requirement — needs to be configured — needs to be policed (whitelist …) Implementation issue: where is this done in the CP? CAC? — Add new member — Change address of member? — Configure policy VPN as a Closed User Group (CUG)

16. Page 15 ===!"§ Deutsche Telekom Innovation Center Scenario: Overlay Model UNI Domain Customer 2 Domain Customer 1 UNI Customer 2 UNI Customer 1 Network Operator Domain CNM Customer 1 NMS Network Operator NMI („X“) VPN as a (CUG) SLA

17. Page 16 ===!"§ Deutsche Telekom Innovation Center Scenario: Overlay Model Implementation effort comparatively low — UNI required — PE must implement mapping of private (CPI) addresses, if these are used in the — Implementation and configuration of policing functions within provider network Membership information needs to be distributed offline and configured manually in the CEs. Acceptable, if customer network is static (e.g. customer network may mainly consist of L2 and L3 devices. This may be the normal case) Resilience features can be used as far as they are supported by the UNI (UNI2.0) Dynamic services. Assessment

18. Page 17 ===!"§ Deutsche Telekom Innovation Center Scenario: Overlay Extension Model Implementation effort higher compared to Overlay Model — UNI required — PE must implement mapping of private (CPI) addresses, if these are used in the — Implementation and configuration of policing functions within provider network Plus: — BGP — BGP VPN Discovery attractive only, if network structure is highly dynamic Assessment } additional effort

19. Page 18 ===!"§ Deutsche Telekom Innovation Center Scenario: Virtual node Description GMPLS enabled BB “Virtual Node” CD Views on the NW: NW: One Routing Domain CE

20. Page 19 ===!"§ Deutsche Telekom Innovation Center General Scenario: Two Providers in parallel Description CD NW: CE CD CE Provider1 Provider2 Scenario supported by any L1 transmission scheme. leased line dynamic leased line overlay / extended overlay virtual node, virtual link per VPN Peer

21. Page 20 ===!"§ Deutsche Telekom Innovation Center Scenario: Virtual node Implementation effort higher — UNI required — PE must implement mapping of private (CPI) addresses, if these are used in the — Implementation and configuration of policing functions within provider network — BGP — BGP VPN Discovery Plus — Protocols providing transport of customer routing information attractive only, if — real time dynamic services are required — network structure is highly dynamic and — CP routing is used in the L1VPN domain as a whole (see previous slides) attractive for carriers carrier not needed by broadcasters Assessment } additional effort

22. Page 21 ===!"§ Deutsche Telekom Innovation Center Scenario: Virtual link Description NW: virtual link topology distributed via routing protocols PD PE PD PE PD PE Routing info exchange on: CE-PE links remote customer sites virtual links TE link attributes (abstraction of the provider NW determined from data link properties) CE PE CE data link resources exclusively allocated to virtual link/VPN TE Link attributes e.g.: latency performance shared risks

23. Page 22 ===!"§ Deutsche Telekom Innovation Center Scenario: Virtual link Dedicated resources — scheduling can be performed internally, resources always guaranteed by provider — effect of resource sharing smaller than in overlay and virtual node. Properties of links known and distributed via routing protocols — Customer has all knowledge to configure properties of e2e-connections availability performance latency … — SLA on basis of links? — Less sharing of operation and management infrastructure — Integration of provider network via CP protocols possible. Attractive for broadcasters for scheduled applications, where100% call success is required. Attractive for guaranteed availability, latency for SANs, performance for live events (jitter) Assessment

24. Page 23 ===!"§ Deutsche Telekom Innovation Center Scenario: Per VPN Peer Description NW: virtual link topology distributed via routing protocols PD PE PD PE PD PE Routing info exchange on: CE-PE links remote customer sites partition portion of provider NW: virtual links with TE attributes virtual nodes CE PE CE data link resources exclusively allocated to virtual link/VPN TE Link attributes e.g.: latency performance shared risks PE PD virtual node

25. Page 24 ===!"§ Deutsche Telekom Innovation Center Scenario: Per VPN Peer Dedicated resources — scheduling can be performed internally, resources always guaranteed by provider — effect of resource sharing smaller than in overlay and virtual node. Properties of links known and distributed via routing protocols — Customer has all knowledge to configure properties of e2e-connections availability performance latency … — SLA on basis of links? — Less sharing of operation and management infrastructure — Integration of provider network via CP protocols possible. Effort higher without added value, may be reasonable only for large networks or critical parameters. Assessment

26. Page 25 ===!"§ Deutsche Telekom Innovation Center Scenario: Management based model If there is no explicit need for near real-time provisioning of connections, management based service models are the better choice: easier to implement setup functionality (is a subset of management functionality of the provider) easier to implement mapping of private names to public names (can be done in one database) easier to implement policing (only one interface has to be policed and compared with the SLA) easier to implement security (only one interface has to be supervised, standard technology) easier to provide value added management functionality such as advanced management functionality (see benefits). easier to offer outsourcing (as the customer view is a subset of the operator’s view). Assessment

27. Page 26 ===!"§ Deutsche Telekom Innovation Center Summary n VPN features are: — virtualization of resources — virtualization of operation -> outsourcing n Virtualization of resources: — high technical effort by CP — trade-off between resource spending and penalties difficult due to unknown user behaviour — only acceptable for customers, if no special requirements regarding latency, security,.. n Virtualization of operation is attractive for customers — Sharing of management system infrastructure — sharing of operational support — less attractive the higher the functionality provided by the network is … — … can be achieved by management as well …. make it simple !!! start with management Shared data plane vs. dedicated data plane

28. Page 27 ===!"§ Deutsche Telekom Innovation Center Requirements for Broadcasters Management — Detailed billing, potentially allocation to specific, broadcaster internal projects — Integration with electronic order management. — Fluctuation of nodes without new SLA negotiations with operator low Topology: — Integration of quasistatic star-shaped network connecting the local studios with the headquarters of the “Landessender” — Transfer to satellite uplinks and DVB-T transmitters. — Dynamic for broadcast production house — Potentially in future: Video on demand SAN-like applications for internal production purposes (archive for movies). Management and Topology

29. Page 28 ===!"§ Deutsche Telekom Innovation Center Requirements for Broadcasters (ctd.) Requirements for these applications — Resilience — Latency — Performance (BER, ES, …) — Performance (SNR …) for transparent networks — Scheduling 100% call establishment success (for live events) call establishment success < 100% (for production; file based) LAN-WAN-connection Presumably, broadcasters do not have the requirement to interconnect several medium or large L1 networks Requirements

30. Page 29 ===!"§ Deutsche Telekom Innovation Center Requirements for Broadcasters (ctd.) Business Model — Broadcasters buy: own equipment lease fibers on long term from different providers outsource operation to small providers; CPEs from this operator — Alternative solutions based on VPNs must provide benefits for broadcasters concerning cost structure flexibility performance ease of interfacing to existing production control systems on the broadcasters' side Scenarios — CUG: incoming calls from post production studios — Outgoing calls to post production studios and co-operating broadcasters  Make it easy - listen to the broadcasters' needs and try to accommodate utilizing a re-usable solution Business model and scenarios } should be easy to handle