About this document
This document introduces a general use case of the Expereo XCA Edge solution. As
it deals with a linear and chronological example, it is a perfect tool to understand the
underlying concepts of our product. It will also help you if you need an overview of all
the benefits you could get from XCA Edge.
Note that this use case only covers one of the several usages of XCA Edge.
However, there is a good chance that a large part of this use case applies to your
own configuration. If not, please have a look to the other use cases.
Moreover, if you need more specific information, please refer to the XCA EdgeAdministrator Manual. It contains a more precise description of the XCA Edge
features, and provides per-page explanations of the graphical user interface.
Abstract
Foo&Sons is a growing multi-national company. It has a strong need for high quality
connectivity, for both inbound and outbound connections. The company IT manager
is concerned about traffic to Foo&Sons website. It is becoming more and more
crucial to the business and already faces quality problems. Foo&Sons also needs to
maintain proper connectivity to specific remote web sites and portals, as it provides
an access to cloud-based applications to its employees.
Therefore, Foo&Sons needs a better understanding of its transits / IX peerings
usage. XCA Edge provides the company with a set of reporting tools to evaluate its
per-transit or per-destination traffic load. XCA Edge will help the company to build a
smart peering strategy or evaluate its need for new transits.
Situation Solution
Lack on information on transitsusage.No way to check if links aresaturated.
Use the transits related reportingtools to evaluate how is the trafficdivided into the several transits.
Lack of information on trafficdestinations (to eventually set upnew IX peerings)
Use the destinations related reportingtools to evaluate the per-destinationtraffic.
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1. Introduction
1.1. Context
Foo&Sons has been using XCA Edge for several months now. Through its main data
center, Foo&Sons provides its collaborators with an access to cloud-based
applications. These applications, mainly provided by CloudService, are critical to
Foo&Sons business. Foo&Sons data center also houses a website that is at the core of it
sales.
So far, Foo&Sons needs an Internet access which allows both a good link quality to
cloudservice.com services but also must be efficient enough to distribute traffic to any
Internet user.
To have the best access to CloudService website, the company established several
peerings through a well chosen Internet eXchange point. Foo&Sons data center is
also connected to high performances transits, through which its web pages are sent to
the users.
Figure 1: Foo&Sons network architecture
1.2. Issues
Foo&Sons do not want to face any link quality problems. As the company is
currently growing, more and more users should connect to its websites, and
Foo&Sons might also hire several new employees. The network administrator has
already recorded several link overloads, while other links were unused. Hence, he
wants to solve several problems:
• Saturated links,
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• Low Transit/IX peering usage, under established SLAs,
• Traffic bursting over contracted CDR.
Before considering establishing new peerings/transits, the network administrator
needs a perfect visibility over its currently used bandwidth, and evaluate how is its
traffic distributed in terms of source or destination subnets/AS.
He has to meet several needs:
• Monitor its links to CloudService services (availability, response time, ...),
• Check its current bandwidth usage over each transit/IX peer, and if no link is
saturated,
• Evaluate the subnets with which its exchanges the most important traffic
(inbound or outbound),
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2. Use case steps
2.1. Step 1: Monitoring setup
First of all, the network administrator needs to set CloudService servers as explicitly
monitored. This will allow to monitor CloudService servers availability.
Actually, XCA Edge can trigger automatic alarms whenever a remote subnet link
properties do not comply with a given set of rules. Alarms have several levels of
severity, from informational to critical error. The network administrator can
configure if an alarm might be notified by email or SMS. A map, available in the
Geolocation / Map section, gives a geographical view of remote subnets statuses.
Note that only monitored subnets are eligible for XCA Edge automated routing optimization.
The network administrator will have to perform several tasks:
• Set up manual probes towards CloudService servers,
• Define the monitored parameters of the enclosing subnet,
• Set up subnets locations.
The mandatory steps to achieve this procedure are exposed in the "Optimized IPSec
WAN" use case. Please refer to this document if you need more information.
2.2. Step 2: Evaluating the per-destination traffic
We now consider that all probes, transits, routers are properly configured. The
network administrator accesses the Traffic / Destination section. This section
provides two reporting tool that help understanding which destinations are the most
important to Foo&Sons business.
The network administrator accesses the "Top X" reporting page, as depicted by
Figure 2. This includes two pie charts illustrating the per destination distribution of
its traffic. Several display options are available:
• Aggregate destinations per subnets or per AS,
• Sorting,
• Period over which data is aggregated,
• Choose the number of top subnet/AS explicitly depicted on the graph. Others
are displayed in gray and designated as "Others"
The left pie chart shows the inbound traffic distribution: this indicates from where
the inbound traffic is coming from. Within the AS mode, the Foo&Sons administrator
notices that the top 5 AS include almost 40% of the total inbound traffic.
Consequently, having a good connectivity towards these AS will be determining to
Foo&Sons business.
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Figure 2: The per-destination traffic
On the right pie chart, the network administrator can check the most targeted
destinations by outgoing traffic. As with the inbound graph, that will help him to
plan new transits contracts.
Finally, the bar graph in the middle illustrates the inbound/outbound traffic ratio.
The Foo&Sons network administrator knows that the first from displayed
destinations is reachable through the IX point, but no peerings were established. On
the right side of the screen, he can select in the drop-down list a filtering transit. He
notices that the same destination is almost routed exclusively through only one
transit, and consequently causes a cost increase.
Therefore, the network administrator envisages to establish a new peering with the
corresponding AS owner. This will reduce the currently used transit overload and
improve the traffic performances towards theses destinations.
2.3. Step 3: Checking the per-transit bandwidthusage
The network administrator now accesses the Traffic / Transits section, and clicks on
the History tab. This page displays two temporal graph (outbound and inbound) of
the per-transit bandwidth usage (Figure 3). He selects the last month period with a
24h data aggregation. He selects the Mbps type to display the bandwidth usage in
Mbps, and then clicks on Apply.
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Figure 3: Transit load over time
On the right, he selects the data to be displayed. By checking the CDR boxes, he
can evaluate if the bandwidth usage bursts over the CDR. The 95th percentile, used
to charge traffic exceeding the CDR, can also be displayed. When the 95th
percentile is getting close to the CDR limit, the network administrator might
consider two solution: either contracting new transits or use XCA Edge optimise the
traffic routing.
The network administrator notices that the IX transit load is very high compared to
the other transits. As the IX transit has a limited capacity, he wants to solve this
overload. By using the per-destination report, he can estimate which destinations
take the most important part of the bandwidth, and notice that several destinations
could be routed through the normal transits.
These destinations could be rerouted through the transits by announcing proper
routes within the IX point. However, before taking any decision, he accesses the
load balancing report. This will provides him with a better view over each transit/IX
transit usage.
2.4. Step 4: Evaluating the per-transit and per-next hop load balancing
To perfectly understand how the traffic is divided between the several transits or IX
point next hops, the network administrator can use the Traffic / Transits / Load
balancing tool (Figure 4). It displays two pie charts analogue to the ones of the top
X reporting pages, as the left chart is for inbound traffic and the right one for
outbound.
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On the top settings bar, the network administrator can select a period displayed. He
can also aggregate data per next-hop or per transits.
First, he chooses to evaluate a per transit distribution of the traffic.
Figure 4: Per-transit load balancing
The network administrator notices that the IX transit takes a large part of the
traffic, as supposed in the previous step. However, he wants to check if the load is
balanced between the several next-hops within the IX point.
On the IX transit, several next-hops can be used. The network administrator selects
the next-hop mode. Using this mode, he can estimate with which next-hops he
exchanges the most important traffic. To evaluate this load balancing within a single
IX transit, he applies a filter thanks to the right panel drop-down list.
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Figure 5: Per-next-hop load balancing within one IX point
He notices that that one of the next-hops uses a large part of traffic, this next-hop
is the one from CloudService. As this peer usage is going over the contracted CDR,
the network administrator thinks about reducing this peering usage. So far, several
solutions might be considered.
Concerning incoming traffic, the network administrator could, as a example, choose
to set up a connection to an other IX on which the same peer is connected to. The
network administrator could configure the router so that they announce that the
route is longer through one IX than another, and therefore force the traffic from
distant subnets to use the other IX.
Outbound traffic routing could be automatically optimized thanks to the XCA Edge
Routing Decision Engine. Please refer to the "Mixed IPSec / MPLS-VPN network
optimization" use case for more information on available routing optimizations.
However, rerouting the traffic could not be a good solution. This might impact the
traffic performances. Therefore, the network administrator would like to evaluate
each link (transit or IX peering) performance.
2.5. Step 5: Dealing with overloadingdestinations.
To take the right decision, he accesses the Probing / Summary menu (Figure 6). As
explained in the "Optimized IPSec WAN" use case, he is able to compare each
transit performances towards these destinations, and notices that the IX transit has
the best RTD and faces no packet loss. As these destinations represent a large part
of the traffic, the network administrator choose not to reroute the traffic through the
normal transits.
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Therefore, he plans to upgrade its IX point connection by increasing the contracted
CDR.
If the normal transits had better or equivalent performances, rerouting the traffic
would have been interesting. XCA Edge provides a set of routing optimization tools
that are described within the "Mixed IPSec / MPLS-VPN network optimisation" use
case. Please read this document to understand how XCA Edge can optimize your traffic
routing.
Figure 6: The Probing / Summary section
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3. Conclusion
The reporting tools have been useful to perfectly understand how is Foo&Sons
traffic distributed, either over destinations or transits. The network administrator is
now aware of its current situation and has been able to take wise and steady
decisions. He has all necessary information to plan new transit contracts or
peerings.
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