Presenter: Dumitru Benchia GS MS NPO Capability Management

1. Global information session sharingIP Backbone - IP Planning OverviewTuesday, 08.07.2008, 10:00 - 11:30 Finish time (GMT + 3) Presenter: Dumitru Benchia GS MS NPO Capability Management

2. Agenda • Introduction • Design documentation • Example topology • Architecture • Planning issues • Design objectives and constraints • Network topology • Addressing • IGP • BGP • MPLS enabled applications • Network management

3. Introduction • Part of a global IP planning pool specialized in Mobile Core systems: HLR, FMC/IMS, GPRS core, IP-BB • Responsibilities: • participate in projects • support the sales teams during tender phase • support the IP planning community world wide • Planning documentation in-line and synchronized with project implementation procedures • Design documentation package includes: • DNP: site connectivity planning • EPF: engineering planning

4. Design documentation • Current task for Capability Management - making the planning template for the IP Backbone solution • The reference project was T Mobile Germany • As first approach the design documentation package contains • Low Level Design (LLD) - main document • Hardware Configuration (HWC) - router module configuration • IP Addressing - excel spreadsheet containing IP address allocation

5. Example topology

6. Architecture Interconnectivity MPLS Enabled Service connectivity VPNs Traffic Engineering Internet Service A QoS Fast Recovery GRX Service B Other IGP MP BGP Service c Physical network

7. Design objectives and constraints • Identification of design objectives and constraints as described in RfQ and Technical Solution Description (High Level Design document) • Design constraints • customer request/preferences • customer standards and policies • interoperability constraints • Naming and numbering conventions • for device names • interface descriptions • TE tunnel descriptions • VLAN numbering

8. Physical network • Network topology (data link connections) • Transmission network (SDH/Sonnet, DWDM) • Hardware platform details • Software type and version that will be used • Interface configuration issues • MTU • CRC • clocking source

9. IP Addressing • How to address - IP addressing concept • What to address • core network links: P-P, P-PE, PE-PE • loopback interfaces • out of band management interfaces • Device names

10. Core IGP • Choice between the 2 link-state protocols OSPF or IS-IS • In case of IS-IS: • ISO addressing: NSAP address format, system ID syntax • topology: areas, router type (L1/L2) • link cost: general formula (10^12/bandwith), modified cost for traffic engineering • timers for convergence tuning

11. Core BGP • For MPLS L3 VPNs MP-BGP is used between PE nodes to exchange • VPN prefixes using the VPNv4 address family • per prefix MPLS label • A public ASN is usually required • To relax the full-mesh requirement for the iMP-BGP between the scalability mechanisms must be planned - Route Reflectors or Confederations • Convergence tuning • next-hop trigger • multiple paths import

12. MPLS enabled applications - L3 VPNs • Allows for traffic segregation at Layer 3 through the definition of multiple VRF (Virtual Routing and Forwarding) instances on the PE routers • Depending of the communication requirements one or more VRF per service needs to be defined per service • Definition of RD (Route Distinguishers) for each VRF • if Route Reflectors are used it’s good practice that RD is unique per VRF and PE router not per VPN since otherwise, in case of redundant paths only one will be remotely visible • Definition of export and import RT (Route Targets) extended community attributes

13. MPLS enabled applications - Traffic Engineering • TE tunnels are setup with the main purpose of assuring protections (of nodes and links) providing for very fast recovery times using FRR (Fast ReRoute) • The tunnel topology must be planned, i.e. how the tunnels are setup • what are the egress and ingress nodes (P, PE nodes) • one strategy is to deploy a full-mesh of tunnels between the PE nodes • tunnels are unidirectional, so for 2 way communication, 2 tunnels must be setup between any 2 nodes • Paths can be manually configured or the tunnels can be dynamically routed using constraint based routing • Backup tunnels need to be provisioned as well for FRR

14. MPLS enabled applications - QoS • Classification and marking: • definition of IP DSCP values and mapping to the MPLS EXP bits • definition of trust domains - marking should be done as close as possible to the source (CE routers) • Congestion management • definitions of separate ques for different types of traffic and parameters for each queue • Congestion avoidance • definition of WRED (Weighted Random Early Drop) profiles for each traffic class • Policing and shaping

15. Network management • Router access • OoB Ethernet (Vtys) transport protocol, restricting access • console access • User authentication • AAA protocol: Radius, TACACS • local user as fallback measure • Monitoring • SNMP - traps, trap collectors • Syslog - server, facility, severity level, local logging • NetFlow • Other services • NTP, DNS

16. Thank you for your attention!