Network Service Assurance

Transcription

1 Service Assurance Embedded 'Always-On' Ethernet Devices for Circuit 'Turn-Up' Testing & In-Service Assurance for Layer- 2 and Layer-3 infrastructures

2 Ethernet (L-2) - Typical Scenario HQ & Operations Centre (NOC) Management Access Management Access Site A Ethernet (Layer-2) Infrastructure Site B Ethernet Service Providers typically offer End-to-End or Core-to-Edge services for their customers, which frequently involve infrastructure, or at the least simple 'tail circuits', from one or more 3 rd party Carriers. In order to verify that actual network performance at all locations within the network are as contracted from the Provider, costeffective test generators and/or traffic 'reflectors' can be embedded between the Provider's demarcation point and the 's LAN Switch or Router hardware at each location, managed from the 's Operations Centre (NOC).

3 Ethernet (L-2) Service Verification Testing 1. Log in to Tester at Site A HQ & Operations Centre (NOC) 4. Results at A can be viewed from NOC console or transmitted to the NOC for inclusion directly to service documentation Site A Ethernet (Layer-2) Infrastructure Site B 2. Set-Up RFC2544 or Y.1564 Test in relation to SLA for service(s) between sites A and B 3. Ethernet (L-2) Test traffic generated at A is looped back at B (SA/DA swapping, via 'SAM' hardware) for analysis back at A In order to verify that the Service Provider(s) have provisioned circuits in accordance with the 's requirements, Service Level Agreement (SLA) verification tests can be readily conducted between each location

4 Subsequent 'In-Service' Monitoring Log-In to set up Agreed Service Parameters (SLA) NOC Log-In to set up Agreed Service Parameters (SLA) Pro-active SNMP 'Trap' alarm sent to NOC if agreed SLA not met Pro-active SNMP 'Trap' alarm sent to NOC if agreed SLA not met Site A Ethernet (Layer-2) Infrastructure Site B Y.1731 protocol exchanges timestamped test packets in order to monitor service parameters relative to pre-defined customer SLA Subsequently, s may require to monitor that SLA performance metrics continue to be satisfied 'inservice'. Pro-active alarming of potential 'SLA breach' conditions enable quick and effective remedial action.

5 And with L-3 (IP) infrastructures? HQ & Operations Centre (NOC) Management Access Management Access Site A MPLS Layer-3, (IP) Infrastructure Site B If the Service Provider is provisioning a Layer-3 network, typically an IP-VPN, then to enable End-to-End performance testing and monitoring, Layer-2 test functionality alone within the test points is insufficient. Ethernet MAC packets cannot traverse Layer-3 elements of the network and Layer-3 (IP) packets are required. RFC2544 and/or Y.1564 testing is agnostic to packet type, so IP-addressed frames can just as readily be used, provided that the embedded testers support this, along with the necessary IP configuration tools and processes (e.g. ARP for IP Gateway address mapping).

6 And for in-service performance monitoring? Log-In to set up Agreed Service Parameters (SLA) NOC Log-In to set up Agreed Service Parameters (SLA) Pro-active SNMP 'Trap' alarm sent to NOC if agreed SLA not met Pro-active SNMP 'Trap' alarm sent to NOC if agreed SLA not met Site A MPLS (Layer-3, IP) Infrastructure Site B TWAMP-lite controller TWAMP protocol exchanges timestamped test packets in order to monitor service parameters relative to pre-defined customer SLA TWAMP-lite responder For networks including Layer-3 (IP) elements, the 'Two-Way Active Measurement Protocol' (TWAMP) performs a similar role to that of Y.1731 for 'Layer-2 only' networks, i.e. to monitor Latency and Jitter performance characteristics, providing alarms in the event of breaches of the customer's SLA criteria.

7 Ethernet Performance Assurance NT1002/3 NetTESTER Low cost test and/or reflection point (with line-rate Source/Destination Address swapping) for circuit set-up testing (RFC2544 and Y.1564). Also supports Y.1731 and TWAMP-lite for both Layer-2 (Ethernet MAC-addressed) & Layer-3 (IP addressed) services NT1004/5 Advanced test and/or reflection point (with line-rate Source/Destination Address swapping) for circuit set-up testing (RFC2544 and Y.1564). Also supports Y.1731 and TWAMP-lite for both Layer-2 (Ethernet MAC-addressed) & Layer-3 (IP addressed) services. Dual-PSU resilient version available Metrodata'sNT1003 and NT1005 platforms include both Layer-2 and Layer-3 circuit testing and in-service monitoring regimes, offering deployment flexibility for each of Layer-2, Layer-3 & hybrid networks. If deployed permanently in-line, when not being used these embedded test devices simply pass all traffic transparently

8 Example 1: Site-to-Site RFC2544 Test Management Console Corporate HQ RFC2544 performance test can be initiated between various sites throughout the network. Testing verifies maximum bandwidth available and reports Latency, Jitter and potentially Packet-loss Ratio for the link. Remote Locn. 1 Remote log-in at NOC Console: > Configuration > Test initiation > Progress monitoring > Viewing of test reports MPLS (Layer-3, IP) Infrastructure MPLS network 'Edge' Routers Remote Locn. 2 NetTESTER NT1003

9 Example 2: HQ-Branch link testing Management Console Corporate HQ Y.1564 performance tests can be conducted to any remote branch location, independently of other links which may be running live data. Testing verifies that 'Committed Information Rate' is being achieved and reports Latency, Jitter and potentially Packet-loss Ratio for the location, whilst regular traffic to other sites is running through the HQ link. NetTESTER NT1003 Branch Locn. 1 Remote log-in at NOC Console: > Configuration > Test initiation > Progress monitoring > Viewing of test reports Single physical 'shared pipe' network connection MPLS (Layer-3, IP) Infrastructure MPLS network 'Edge' Routers Branch Locn. 2 NetTESTER NT1005 with dual-redundant PSU Branch Locn. 'N'

10 Example 3: HQ-Branch monitoring Management Console Corporate HQ TWAMP 'background' monitoring can be used to generate alarms to the Operations Centre in the event that (Latency, Jitter, Packet-Loss) becomes out-of-specification and breaches pre-defined 'Service Level Agreements' for each link. Remote Office 1 NOC Console: > Configuration of SLA thresholds > Initiation of background monitoring > SNMP 'Trap' alarm reception (SLA breach) > Further investigation by individual unit log-in MPLS (Layer-3, IP) Infrastructure MPLS network 'Edge' Routers Remote Office 2 NetTESTER NT1003 Remote office 'N'

11 Typical Management View

12 More NT100x family 'Testing' features The Layer-2 and Layer-3 testing so far described, can be conducted across Copper or Fibre WAN links from NetTESTER devices, since all products support copper or fibre (via SFP) connectivity at up to 1Gbps. The NetTESTER family also support additional features for 'Layer-1' testing of either copper or fibre links. As shown in the next slide, a simple 'TDR' test can be applied to the pairs within an RJ45 cable connected to the NetTESTER. If any of the pairs within the cable are 'open' (i.e. not connected, or broken') the distance to the fault is indicated. If the WAN port is connected via fibre, using specifically a Metrodatasupplied 'micro-otdr' Optical Transceiver, then the NT100x will not only be able to indicate the length of the fibre connected, but also can be configured to issue a Management alarm should a fibre be disconnected whilst in-service. The alarm provides both a precise 'timestamp' of the event and the distance to the discontinuity. This is illustrated in the following slides.

13 Simple Cat-5 Copper Cable Test screen In this case, one of the pairs of the Cat 5E RJ45 cable is shown as being cut at a distance of 10m from the tester. This view is available at any of the LAN or WAN ports of the NetTESTER device

14 OTDR Fibre cable fault testing/alarming This shows the SFP DDM data from an OTDR-capable Transceiver within the NetTESTER In this case, the fibre has been 'patched' in and out' to several lengths as indicated...

15 Selecting Alarms for TRAP notification Under configuration control, it is possible to select that an SNMP 'TRAP' alarm message is sent from the NT100x in the event of a fibre breakage - the time and distance to the break is recorded within the alarm message

16 Service Assurance Thank you!