Citrix NetScaler is capable of implementing a global web services environment, especially when using the content switching feature. This feature is available from the Citrix NetScaler Free and higher licenses. With the content switching feature, we can use only one WAN IP address for different backend servers. In this way, we can consolidate WAN IP addresses.

If you are using a lot of secure traffic, it's better to use a physical Citrix NetScaler MPX or SDX because of the hardware SSL chip. Besides the SSL chip, please be aware of the generated HTTP requests per second. This number of requests per second is necessary to determine the most suitable hardware for the environment.

When a web service is based on a lot of static website information, we should consider using application acceleration, application security, and frontend optimization. All of these features give a guarantee that the environment is ready to deliver the best performance for every device, and protect the environment.

Application acceleration will be used to cache from pages whenever possible. This will ensure that the pages that are requested by users more often will get the page from Citrix NetScaler instead of the web server at the backend. This offloads the backend web server.

Nowadays, Distributed Denial of Service (DDoS) is very hot item. This is because a lot of environments are getting DDoS attacks. Citrix NetScaler is capable of preventing these kinds of attacks.

With frontend optimization, we can optimize traffic for different devices. For example, we can convert GIF images to PNG, optimize JPEG files by removing non-image data, optimize CSS files, and so on. This optimization will ensure that websites can be loaded fast from every type of device and connection.

As we can see in the preceding figure, we're using only that IP address that needs to be available from the public Internet. Based on the expression, we can define to which load balancing virtual server the Citrix NetScaler content switching should connect.

To have a trusted and secure connection, it's best to use a secure connection based on 443 when the web service needs this. The Citrix NetScaler content switching supports the SNI feature. With the SNI feature, we can to bind multiple certificates. We can specify subdomains in this feature too. Internally, the Citrix NetScaler appliance parses the certificates and extracts the domain names. Citrix NetScaler stores these domain names in a hash table.

So, for global web services, it's better to use the Citrix NetScaler Platinum Edition based on a physical appliance. This edition allows us to use all the necessary features that leverage quality and speed for the web service environment.