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If you have any questions about the Nexus Watch service please
see the sections below. If you still cannot find the answer,
please email enquiries@nexuswatch.com
and we will be happy to be of assistance.
Please choose a section:
General Questions
Free Trial
Nexus Watch Pricing
Tests
Events and Alerts
GENERAL QUESTIONS
I already have a network management system. Why should
I use Nexus Watch?
Most network management systems are
designed to monitor network equipment (hubs, switches, routers
etc) from inside your network. Just because your network and
servers are working, it doesn't necessarily follow that your
customers can get to your site or that they are getting acceptable
performance to keep them there.
Nexus Watch monitors your Internet services (DNS, HTTP, FTP,
etc), over the Internet just as if it were an electronic customer
connecting to your site from their home or office. It reports
the true customer experience by measuring the end-to-end system,
including the Internet itself.
What's all this business with multiple ISP's?
When you configure Nexus Watch to perform a test (eg: download
a page from a web server), the test is performed through more
than one ISP (Internet Service Provider) at the same time.
The Nexus Watch pollers, which perform the tests, are each
connected to the Internet via different ISPs. When a test
is performed, the pollers are triggered to perform the same
test at exactly the same time, but through different paths
along the Internet.
This is a vital part of the test, and is one of the main
differentiators between Nexus Watch and other services. If
there is only one poller then we can never be sure whether
performance or availability problems are that of the ISP or
of the test subject. By examining results obtained through
different ISPs we can obtain a much better picture of where
performance issues lie. This only works if the tests are performed
at precisely the same time (as Nexus Watch does), otherwise
we cannot make a true comparison.
Where are the Nexus Watch pollers located?
At the present time there are two Nexus Watch pollers, each
installed in facilities in London’s Docklands and connected
to different ISPs. We will be extending the service with more
Nexus Watch pollers connected to multiple ISPs across the
world. This will provide our customers with a view of the
performance of their Internet based services from all around
the world.
If you have an interest in seeing statistics obtained through
a particular ISP, or from a particular geographical location
(including from within your own infrastructure, or from a
particular customer) please contact enquiries@nexuswatch.com.
We are able to make special arrangements to suit your needs.
Does Nexus Watch require any hardware or software to be
installed on my systems?
No. This is one of the key advantages. Nexus Watch acts just
as if it were one of your customers. It accesses all of your
services in the same way that they do, but can still obtain
a large amount of important information.
Because no special hardware or software needs to be installed
at your site, Nexus Watch offers the following benefits:
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Very
quick to set up. Management can be achieved just minutes
from now! |
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Requires
no investment in technologies that will quickly become
outdated and need replacing. |
|
Requires
no specialist knowledge of setting up management systems.
|
|
Requires
no operations staff to monitor the management systems.
|
|
Requires
no downtime of your systems. |
Can Nexus Watch harm my systems?
Nexus Watch is very safe. It only uses services that you have
made available on the Internet. Unlike with most network or
systems management, there is no connection to your internal
networks or computers.
To protect you from accidentally setting a polling interval
so low that it could put adverse load upon your server, the
minimum polling interval is set to 5 minutes by default. Nexus
Watch is capable of polling more frequently, and one of our
operations team will be happy to reduce your minimum allowed
polling interval upon request.
Does availability of bandwidth affect the results of my
tests?
We ensure that Nexus Watch has more than enough bandwidth
available at each of the pollers to perform all of the tests
that our customers configure. The bandwidth used is continually
monitored and upgraded well in advance of reaching the maximum
allowed by the connections. The exact polling algorithm used
is the result of much research and development and ensures
that polls can not interfere with each other. The web interface
is connected separately to the Internet, so heavy use by users
will not affect the results.
You can be sure that the statistics gathered are not skewed
by the performance of the Nexus Watch system or its connections
to the Internet. Of course the performance of the rest of
the Internet will affect your results, but that is the nature
of the Internet and the same applies to your customers connecting
to your site. This is why Nexus Watch reports the true customer
experience.
Does the performance of the Nexus Watch hardware affect
the results of my tests?
No. The Sun Microsystems hardware that Nexus Watch runs on
has plenty of performance capacity built in. In addition,
all system statistics are continually monitored to ensure
that your tests are unaffected.
What other services can be purchased with Nexus Watch?
We can provide a consultancy service to examine your statistics
and write a regular report giving interpretations and recommendations.
We also offer other specialist consultancy services, and training.
Nexus Watch is a service provided by Parallel.
Parallel is a specialist network and systems management company
that has the expertise and experience to install custom-built
network and systems management solutions to suit any requirement.
Customers include Alcatel, Vivendi Universal, BNP Paribas,
HOT Telecom, and many other world-leading companies. For further
information call Parallel on 08700 727255, email enquiries@parallel.ltd.uk,
or visit www.parallel.ltd.uk.
FREE TRIAL
What is the free trial?
We offer a one month free trial of Nexus Watch to all prospective
customers. The trial allows you to try all of the features
offered by Nexus Watch in full. It is an opportunity for you
to see first hand if Nexus Watch can meet your requirements.
Because Nexus Watch is designed, produced and operated by
Parallel, we have the ability to swiftly modify any functionality
to meet your exact needs and would be happy to meet you to
discuss your requirements.
What are the limitations of the free trial?
The functionality of the free trial is exactly the same as
that of the subscription service. There is, however, a minumum
polling interval allowance of 10 minutes. In the subscription
service polling may as frequent as once per minute, depending
upon the level of service purchased. During your free trial,
we only permit you to configure two tests of each type and
allow only 10 pager/SMS messages to be dispatched. For the
subscription service, the upper limit of both will depend
upon the level of service purchased. If you feel that you
need more pager/SMS credits or a lower polling interval for
the trial, please contact
us.
What will happen at the end of the free trial?
Seven days prior to your free trial expiring we will contact
you to remind you. You will have no obligation to purchase
a subscription, and you will owe us nothing. If you do decide
to purchase a subscription, we can keep any existing data
from your free trial and include it in your new account. Whether
you decide to purchase a subscription or not, we would be
very grateful of any comments you have about our service.
Please email comments to enquiries@nexuswatch.com
How do I sign up for the free trial?
You may sign up on-line by clicking the FREE
TRIAL button at the top of the home page. Alternatively,
contact our sales department
and someone will be happy to set up an account on your behalf.
Why do you require my email address?
Following registration, your password will automatically be
sent to you by email. For security reasons we must confirm
your identity, so this process confirms that you can be contacted.
We will not pass your details on to any third party. For further
details, please see our privacy policy.
Why won't Nexus Watch accept my email address during registration?
For security reasons we do not allow some email domains to
be accepted during on-line registration, and these include
all popular web email accounts. We also only allow one demo
account to be set up per email domain. If you find that your
email domain has been blocked, but you have not had a trial
account before, please
contact our sales department who will be happy to create
a demo account for you using any email address that you wish.
If you have an existing demo account but would like to extend
your trial period, please contact
us.
NEXUS WATCH PRICING
How much does Nexus Watch cost?
Because the requirements of every customer are different we
do not publish a price list. We will tailor-make a package
especially for you, with your desired tests, polling intervals
and alerting mechanisms. Because Nexus Watch is both developed
and provided by Parallel, the established and award-winning
network management consultancy, we have the skills in-house
to ensure that what you buy matches your precise needs. We
can also provide Nexus Watch as part of a larger integrated
network and service management solution. To discuss your requirements
further and to obtain a proposal please contact
our sales department.
TESTS
What services can Nexus Watch measure?
At present, Nexus Watch supports the following services: HTTP,
HTTPS, FTP, and DNS. Through our Content Checking test, we
can also verify the results of server side processes. These
are described in more detail in the following sections.
What services will Nexus Watch support in the future?
Our aim is for Nexus Watch to support every Internet service
that is in use today, and to provide some clever analysis
tools. Our development team are working on many new additions
to the service. We can also develop special tests that are
specific to your site – even using proprietary protocols.
We will be launching our security suite in the very near future.
Please contact us for
further information.
What is the HTTP Test, and how does it work?
The HTTP test is designed for monitoring your HTTP servers
and web pages. Unlike services offered by other companies,
our HTTP test does much more than just downloading a web page!
Getting a web page successfully over the Internet depends
upon a number of factors. First, the client browser needs
to know the IP address of the server, and will use DNS to
perform the lookup. Poorly performing DNS servers will affect
their overall experience. There’s also the question of whether
DNS queries and web pages have been cached somewhere along
the line. In-line objects (JPEG’s, Flash documents etc) can
be stored on different servers and will also affect the overall
page response.
Nexus Watch takes all of these points into consideration,
and performs a number of tests. The DNS response time is first
tested. To ensure that the results are consistent, the test
is performed twice and the second result logged. This ensures
that any DNS caching that may be configured to occur anywhere
along the path is taken into account. We can never prevent
an intermediary system from caching the requests (as they
are beyond our and your control), but we can force caching
to occur if it has been configured to do so by repeating the
test. This is the only way to produce consistent results.
Next, the web page is downloaded twice (for the same reason
of forcing any possible caching to occur). The HTTP connection
time is logged separately from the download time of the page
and all of its in-line objects. This helps you distinguish
between a slow network (where connection time will be high),
and a possible slow server (where transfer rate is low, but
connection time is low).
When you configure a report for a HTTP test, you are able
to see the results of these “sub-tests”.
Of course, as with all of the Nexus Watch tests, the HTTP
test is performed simultaneously via multiple ISPs to help
you distinguish between problems with you system and ISP problems.
The Nexus Watch HTTP test supports downloading of pages that
require logins. Just enter the login name and password on
the test configuration page.
Nexus Watch will repeat the test at intervals set by the Polling
Interval field on the test configuration page.
You may configure error and threshold events to watch out
for, and optionally have Nexus Watch send you an alert if
it sees them.
What is the HTTPS Server Test, and how does it work?
The HTTPS Test is exactly the same as the HTTP test, except
that it is for secure HTTP transactions that use SSL.
Like the HTTP Test, the HTTPS test also supports logins.
What is the DNS Server Test, and how does it work?
The DNS Server test has been designed to monitor the availability
and performance of a particular DNS server.
When you configure the test, you are asked for the DNS server
address. You can supply either the fully qualified hostname
(eg: dns0.mydomain.com) or it’s IP address.
The test is performed by querying the DNS server for it’s
own address, which it will always know without the need for
consulting other servers.
Because DNS uses UDP as the transport protocol, there is no
such thing as a “connection time”. However, at Nexus Watch
we feel that it is important to try and distinguish between
network response and server response as much as is possible.
The DNS Server Test therefore has a sub-test that performs
an ICMP echo (“ping”) of the DNS server at the same time.
Because a ping packet will not involve any processing by DNS
software (such as “Bind”), it gives a metric for the performance
of the network between Nexus Watch and the server.
Please note however, that depending upon the configuration
of the server and the network to it, ICMP packets may be given
different priority or may even be blocked. This sub-test is
therefore of most value when you know the network configuration
by your DNS server.
The test configuration also allows you to specify what to
do if you don’t get a response. The very nature of UDP as
a transport protocol can mean that not getting a response
first time is acceptable (as it is a connectionless protocol).
You can configure the amount of time to wait for a DNS response
(the “timeout”). You can also configure how many times to
retry (the “retry” value), and how much to increase the timeout
by between retries (the “timeout multiplier”). Only after
retrying the specified amount of times will Nexus Watch generate
an event if there is still no response.
Nexus Watch will repeat the test at intervals set by the Polling
Interval field on the test configuration page.
You may configure error and threshold events to watch out
for, and optionally have Nexus Watch send you an alert if
it sees them.
What is the DNS Lookup Test, and how does it work?
The DNS Lookup Test measures the speed of looking up a particular
address, using the DNS system.
DNS is a globally distributed system comprising many thousands
of servers all sharing information. What is most important
to many companies is the speed at which their web (or any
other) address is looked up using the system as a whole, and
not the performance of a particular DNS server (which is covered
in the DNS Server Test).
All Internet addresses are defined on an authoritative server
first of all. The authoritative server for a particular address
is the only server that can say with 100% certainty what IP
address a particular host name has or vice-versa. Other DNS
servers will either take occasional copies of the authoritative
server tables, or they will ask the authoritative server when
they are themselves asked. Queries can move up a chain of
DNS servers in order to find the answer. Servers will normally
cache responses for a period (the “Time to Live”, or “TTL”).
When you configure the DNS Lookup Test, you are asked to specify
the address to lookup. This can be a fully qualified hostname
(for a forward lookup, to get the IP address), or the IP address
(for a reverse lookup, to get the host name).
As with all tests, Nexus Watch performs the DNS Lookup Test
simultaneously via multiple ISPs. The DNS server local to
each of the Nexus Watch pollers is queried for the address.
This is performed twice by each poller so that caching of
results does not produce inconsistent and misleading results.
The test then establishes the authoritative server for the
address provided, and queries it directly for the address.
Results are shown individually in the DNS Lookup reports.
The test configuration also allows you to specify what to
do if you don’t get a response. DNS uses UDP as a transport
protocol. The very nature of UDP means that not getting a
response first time is acceptable (as it is a connectionless
protocol). You can configure the amount of time to wait for
a DNS response (the “timeout”). You can also configure how
many times to retry (the “retry” value), and how much to increase
the timeout by between retries (the “timeout multiplier”).
Only after retrying the specified amount of times will Nexus
Watch generate an event if there is still no response.
Nexus Watch will repeat the test at intervals set by the Polling
Interval field on the test configuration page.
You may configure error and threshold events to watch out
for, and optionally have Nexus Watch send you an alert if
it sees them.
What is the FTP Test, and how does it work?
As the name suggests, the FTP Test is designed for measuring
the availability and performance of FTP servers. Passive and
active FTP servers are supported.
To configure the FTP Test, enter the URL (web address) of
the file (eg: ftp://myftpserver.mydomain.com/pub/myfile).
You may then optionally enter a login ID and password. If
you do not enter these, then an anonymous login is assumed,
and your email address will be given as the password.
In a similar way to how the HTTP Test works, the FTP Test
records three metrics – the DNS lookup time, the connection
time, and the download time. Recording these separately gives
a much better indication of exactly where performance problems
are occurring.
Nexus Watch will perform downloads at intervals set by the
Polling Interval field on the test configuration page.
You may configure error and threshold events to watch out
for, and optionally have Nexus Watch send you an alert if
it sees them.
EVENTS AND ALERTS
What is the difference between an event and an alert?
An event is triggered by an error (eg: site not responding),
or a threshold breach (eg: transfer rate is less than 1kb/s).
You can configure what events you want Nexus Watch to look
out for by going to the Configure Test page for each of your
tests.
An alert is Nexus Watch informing you that an event has been
triggered. For example you may wish to be alerted by email,
pager or SMS to the fact that an event has occurred. Not all
events need to generate an alert. You can configure an event
to log only, and view the log by creating and event report.
What is the difference between a rising and falling threshold?
A falling threshold is breached when the test results fall
below the threshold. For example, imagine a test is measuring
HTTP transfer rate. You may consider that an acceptable transfer
rate is 3kb/s, and want to be informed if the test yields
a transfer rate which is lower than this. In this case you
would need to set a falling threshold of 3.
A rising threshold is the opposite. The event is triggered
if the test results are higher than your threshold. You may
use a rising event for tests such as HTTP download time.
What is a re-arm value?
Using re-arm values minimises repetition of events caused
by a test that is yielding results that are fluctuating around
a threshold.
In the example above of a falling threshold of 3, imagine
that the results were fluctuating around this value (eg: 5.4,
3.2, 2.4, 3.1, 2.7 etc), but in normal circumstances were
above 4.0. We would not necessarily want to generate an event
every time we got a value of less than 3.0, as the problem
is likely to be caused by the same condition. If we set a
re-arm value of 4.0, then Nexus Watch will create an event
the first time the test yields a value of less than 3.0, but
will not create another until the test first returns a value
of more than 4.0 and then drops below 3.0 again.
Falling thresholds should have a re-arm value that is higher
than the threshold. Rising thresholds should have a re-arm
value that is lower than the threshold.
We recommend that you start with re-arm values that are 10%
apart from the threshold.
What is meant by clearing an event?
For error events, such as a site not resonding, the event
is said to have been cleared if the test is performed again
without yielding the error.
For threshold events, such as a transfer rate dropping below
3kb/s, the event is said to have been cleared if the test
is performed again and the results yield a value that is beyond
the re-arm value. For example, for a falling threshold of
3.0 with a re-arm value of 4.0, the event will be cleared
if the test next returns a value of 4.0 or more.
I have received an alert and am now taking steps to fix
the problem. How do I stop Nexus Watch from sending me new
alerts for the same event while I attend to the problem?
Go to the Events Summary page by clicking the Events button
in the menu to the left of the screen. Find the event in the
Event Report at the bottom of the screen. In the Alerts column,
click the suspend button which looks like this:  You
can resume the alerts by clicking the resume button which
will have replaced the suspend button, and looks like this:
What types of alert are available?
Nexus Watch can send emails, pages and mobile phone SMS messages.
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