NetTESTER - Performance Assured

NetTESTER

Metrodata
Embedded 'Always-On' Network Testing &
In-Service Performance Assurance

Is my Network 'up to standard'?

Modern packet-switched networks can exhibit variable quality and performance

At the same time, increasing deployment of performance-sensitive applications such as Voice and Video place stringent demands on network infrastructures

Inadequate or variable performance at the underlying Packet Switching/Routing layers of the network can result in significant application degradation

Users require assurance that Service Providers have provisioned new network links to the agreed specification and that applications will perform as expected

At initial set-up time, typical concerns include:

  • What is the real throughput of my WAN links?
  • What is the level of packet-loss, leading to inefficiency via re-transmissions?
  • What is the transit delay and how constant is it? What is the network 'jitter'?

Network test equipment is often bulky, expensive and complex to use, so how can performance be verified 'on demand' at any time, simply and cost-effectively?

Does network performance vary over time?

Even if performance is verified at the time of installation of a new network link, this may not be enough...

Is the 'day 1' performance sustained as network load increases?

  • Does network performance vary with time of day, or across a month?
  • How common are 'outages', what is the downtime percentage of the network?

Active, in-service networks cannot frequently be taken out-of-service for comprehensive testing, so is non-invasive monitoring possible?

Is it possible to receive pro-active alarm notifications at our Management Centre if one or more performance characteristics is impaired for any network link?

The answer to all of these questions is 'Yes'!

NetTESTER from Metrodata addresses the needs of both Telecoms Carriers and Corporate Enterprises, for cost-effective testing and in-service monitoring of network performance.

NetTESTER family

NT1003: Low cost test probe for circuit set-up testing (RFC2544 and Y.1564) for services of up to 1Gbps. Also supports in-service monitoring via Two-Way Active Measurement Protocol, or 'TWAMP' for Ethernet Switched and IP-Routed network infrastructures.

NetTESTER: NT1003

NT1005: Advanced test probe for circuit set-up testing and in-service monitoring. Can be left permanently 'in line', transparently passing regular LAN-WAN traffic in both fibre and copper deployments. Dual-PSU resilient version available.

NetTESTER: NT1005

NT10G05: Advanced test probe for services of up to 10Gbps.

NetTESTER: NT10G05

Ethernet WAN Service: Typical Scenario

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 3rd party Carriers. In order to verify that actual network performance at all locations within the Customer network are as contracted from the Provider, cost-effective test generators and/or traffic 'reflectors' can be embedded between the Provider's demarcation point and the Customer's LAN Switch or Router hardware at each location, managed from the Customer's Network Operations Centre (NOC).

Ethernet WAN: Circuit Activation Testing

In order to verify that the Service Provider(s) have provisioned circuits in accordance with the Customer's requirements, Service Level Agreement (SLA) verification tests can be readily conducted between each location.

Ethernet WAN: Circuit Activation Testing

In order to verify that the Service Provider(s) have provisioned circuits in accordance with the Customer's requirements, Service Level Agreement (SLA) verification tests can be readily conducted between each location.

Ethernet WAN: Circuit Activation Testing

In order to verify that the Service Provider(s) have provisioned circuits in accordance with the Customer's requirements, Service Level Agreement (SLA) verification tests can be readily conducted between each location.

Ethernet WAN: Circuit Activation Testing

In order to verify that the Service Provider(s) have provisioned circuits in accordance with the Customer's requirements, Service Level Agreement (SLA) verification tests can be readily conducted between each location.

Ethernet WAN: Circuit Activation Testing

In order to verify that the Service Provider(s) have provisioned circuits in accordance with the Customer's requirements, Service Level Agreement (SLA) verification tests can be readily conducted between each location.

What about Layer-3 (IP) Networks?

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).

And for in-service performance monitoring?

For Layer-2 (Ethernet Switched) and/or Layer-3 (IP Routed) infrastructures, 'Two-Way Active Measurement Protocol' (TWAMP) is used to monitor Latency and Jitter performance, providing alarms in the event of breaches of the customer's SLA criteria. By using only occasional test packets, TWAMP does not affect service.

And for in-service performance monitoring?

For Layer-2 (Ethernet Switched) and/or Layer-3 (IP Routed) infrastructures, 'Two-Way Active Measurement Protocol' (TWAMP) is used to monitor Latency and Jitter performance, providing alarms in the event of breaches of the customer's SLA criteria. By using only occasional test packets, TWAMP does not affect service.

And for in-service performance monitoring?

For Layer-2 (Ethernet Switched) and/or Layer-3 (IP Routed) infrastructures, 'Two-Way Active Measurement Protocol' (TWAMP) is used to monitor Latency and Jitter performance, providing alarms in the event of breaches of the customer's SLA criteria. By using only occasional test packets, TWAMP does not affect service.

Typical NT1003/5 Deployment

NT1003/5 typically installed either to a spare port of remote site LAN switch, or to a spare port (via Copper or Fibre) of the Network provider's Edge Router (or Switch / Demarcation Device in the case of a Layer-2 infrastructure).

Alternative 'in-line' NT1005 Deployment

NT1005 can be installed, via Copper or Fibre, in the 'data-path' between Network provider's Edge Router (or Switch / Demarcation Device in the case of a Layer-2 infrastructure) and remote site LAN infrastructure). NT1005 is transparent to regular data traffic in this type of deployment.

Example 1: Site-to-Site RFC2544 Test

RFC2544 performance tests 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.

Example 2: HQ-Branch Network link testing

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.

Example 3: HQ-Branch Network monitoring

TWAMP 'background' monitoring can be used to generate alarms to the Network Operations Centre in the event that (Latency, Jitter, Packet-Loss) becomes out-of-specification and breaches pre-defined 'Service Level Agreements' for each link.

Network Management

NetTESTER platforms can be managed via local terminal connection, or both locally and remotely via simple context-sensitive menus using Telnet/SSH, or via Web Browser applications. Readily integrated into SNMP-based Network Management Console views, NetTESTER offers a comprehensive test and in-service monitoring solution for anything from discrete critical links to the entire Corporate network

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:

  • A simple 'TDR' test can be applied to each of 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 Metrodata-supplied '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 Network Management alarm (via SNMP 'trap' messaging) should a fibre be disconnected whilst in-service. The alarm provides both a precise 'time-stamp' of the event and the distance to the discontinuity. This is illustrated in the following slides.

NT used for OTDR 'dark fibre' service protection

Use of NT1003 with OTDR Transceiver for monitoring of dark fibre typically 'lit' by third party active equipment.

Note: 1625nm iSFC OTDR transceiver wavelength is beneficial in this scenario, as this is beyond the wavelength range used by regular data services, so could reasonabl be excluded from availability of all other wavelengths in the 'dark' fibre.

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...

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