INFN Experience with Layer-2 Services across GÉANT and the DataTAG Testbed March 15, 2004 Tiziana Ferrari INFN - CNAF DataTAG is a project funded by the European Com m ission GNEW2004 – 15-16/ 03/ 2004 under contract I ST- 2001- 32459
Talk Outline � L2 VPNs and the Grid: � use cases and advantages � MPLS L2 VPNs and additional features � MPLS L2 VPNs and DataTAG � The Path resources � Advance Reservation architecture � Features and implementation � Conclusions, requirements and future work GNEW 2 0 0 4 , 1 5- 1 6 March 2 0 0 4 2
L2 Virtual Private Networks and the Grid L2 VPN: connectivity between geographically � dispersed customer sites across MAN or WAN networks as if they were connected using a LAN Grid use cases: � MPLS-based VPNs: a firewall bypass 1. Overlay network set-up: simplicity and flexibility 2. new Grid job scheduling and data replica 3. management models GNEW 2 0 0 4 , 1 5- 1 6 March 2 0 0 4 3
Grid job scheduling and data replica management with L2 VPNs � Today: Computing Elements (CEs) are selected from the site where one ore more SEs hold a copy of the input file which is accessed by the job to be scheduled � L2 VPN: by configuring VPNs which include compute and storage resources from several different data tier levels, CEs can be considered “virtually” local to SEs which are remote from a network point of view GNEW 2 0 0 4 , 1 5- 1 6 March 2 0 0 4 4
Grid job scheduling and data replica management with L2 VPNs (cont) � Advantages: � Jobs can execute on a CE even when a file replica is not locally available -> Richer set of candidate CEs that can run the job � Traffic load at potential Grid bottlenecks can be reduced � Different data replica management policies are possible depending on the Grid application in mind: � Total/ partial data set replication vs No replication GNEW 2 0 0 4 , 1 5- 1 6 March 2 0 0 4 5
MPLS-based L2 VPNs Ethernet/ VLAN traffic is carried by MPLS over the service � provide network (PE and P routers) and then converted back to L2 format at the rx site Security and privacy: policies i the CE routers keep rotes that � belong to different VPNs separated CE: it selects the output circuit to which specific L2 traffic has � to be sent according to: � The VLAN ID present in the 802.1Q frame header (VLAN L2 VPN) � The input interface form which the frame wa eceived (Ethernet L2 VPN) On-demand set-up: CEs can be forced to belong to different L2 � VLANs according to the Virtual Organization (VO) they are allocated to at a given time GNEW 2 0 0 4 , 1 5- 1 6 March 2 0 0 4 6
Example CE2,1 SE2,1 Grid Domain 2 SE2,2 CE2,2 CE1,1 SE1,1 CE1,2 SE3,1 CE3,1 SE1,2 CE1,3 Grid SE3,2 CE3,2 Domain 3 Grid SE3,3 CE3,3 Domain 1 SE3,4 CE3,4 GNEW 2 0 0 4 , 1 5- 1 6 March 2 0 0 4 7
Why MPLS? � A given host can belong to one or more VPNs at a time if native VLAN tagging is enabled � The LSP primary/ secondary path can apply non- standard routing policies � A given diffserv packet forwarding treatment can be assigned to the LSPs associated to a given VPN (MPLS EXP field set by the LSP head-end router): � Grid ftp between SEs: if based on enhanced TCP stacks, it can be handled through the Scavenger/ Less Than Best Effort service (fairness) � CEs/ SEs used for remote visualization with real-time requirements could apply to the IP Premium service � Performance guarantees to individual VOs GNEW 2 0 0 4 , 1 5- 1 6 March 2 0 0 4 8
L2 VPNs and DataTAG Adv Res&Resource Mgr/ Grid Information Service 3com stm64 C7609 C7606 T320 T320 M10 M10 VLAN1, IP Premium VLAN2 LBE/Scavenger GNEW 2 0 0 4 , 1 5- 1 6 March 2 0 0 4 9
MPLS- based VPN advance reservation: the Path � A possible abstraction of the Network Resource � GGF Grid High-Performance Networking RG � Dynamic vs static (-> Grid Information Service) � PATH = concatenation of Path Elements � Path Element: � Across a single domain or a chain of contiguous domains with same control plane � Types: optical, MPLS, Diffserv Virtual Leased Line, ... � Static path attributes: � requested for resource matchmaking � Info about capabilities supported (eg. MPLS signalling) � Authentication/ authorization: eg. AAA, Globus Gatekeeper, etc � Path performance measured by the Grid network monitoring service (GHPN) GNEW 2 0 0 4 , 1 5- 1 6 March 2 0 0 4 10
Advance Reservation Architecture Grid VOMS Authentication Auth DB Role Request + Reply Pseudo Cert Resource GARA Slot USER managers Agent Advance Reservation table request / reply A A A BGP Topology advertisements + BB Reservation indications Policy DB QoS Qos Path Networks Path provision indications request/ reply EDG WS + Service Discovery EDG User Interface/Gara: User Int . Reservation parsing (JDL) . Matchmaking . Reservation identification . GARA APIs, Gatekeeper, Resource manager, LRAM, Resource specific manager GNEW 2 0 0 4 , 1 5- 1 6 March 2 0 0 4 11
MPLS- based L2 VPN management: features � MPLS LSP: � unidirectional � based on a Diffserv path statically provisioned (IP Premium) � Connects the two CE routers of the two leaf domains � Shared by authorized users/ applications generating traffic from the source domain � diffserv paths that support MPLS capabilities (across MPLS-capable transit domains) are indicated by the information system GNEW 2 0 0 4 , 1 5- 1 6 March 2 0 0 4 12
MPLS-based L2 VPN management: implementation � Two given CE routers of two different leaf domains are connected by a single diffserv path of a given type (IP Premium, lbe etc) � Each mpls/ diffserv path is statically associated to a given pre-defined VLAN number � VLAN tagging pre-configured statically on end- systems � Router configuration: � Diffserv: marking and policing (IP Premium only) at the ingress router � MPLS L2 VPN: VLAN tagging and encapsulation, LSPs with QoS and CCC Connections (Juniper) on the LSP head-end router � Topology and routing: very difficult to mange dynamically! GNEW 2 0 0 4 , 1 5- 1 6 March 2 0 0 4 13
Router configuration � MPLS L2 VPN Manager: � Perl application using Junoscript libraries (prototype for Juniper routers) � Configuration script parsing � possible operating system/ configuration scripts mismatches � configuration errors (rollback) � Configuration add/ modify/ delete � Configuration locking GNEW 2 0 0 4 , 1 5- 1 6 March 2 0 0 4 14
Conclusions & requirements � Results: � Optimal TCP performance on MPLS L2 VPNs between StarLight and CERN – 1 Gbps � MPLS EXP field marking and classification: ok (Juniper) � Diffserv scheduling: ok � Requirements: � On-demand set-up of e2e MPLS LSPs (no stitching) � Handling of MPLS EXP field for QoS GNEW 2 0 0 4 , 1 5- 1 6 March 2 0 0 4 15
Future work � Applicability of L1/ L3 VPNs to Grids � VPLS (Virtual Private LAN Services) for multipoint vs p2p ethernet services (MPLS packets from CE routers are broadcast to PEs, i.e. the ISP network is traversed in a p2mp fashion � Enhancement of the advance reservation system � Multiple vendors � Interdomain scenario � Co-allocation, storage adv res � Software rewriting (OGSA compliance) � Formal definition of Grid VPN Service � Type of Grid Connectivity service � GHPN GNEW 2 0 0 4 , 1 5- 1 6 March 2 0 0 4 16
Recommend
More recommend
