Solution Brief: Mobile Operators - How to control Skype
Skype Voice over IP threat to
Skype has been installed by over 250.000.000 users
worldwide, mainly on their PCs to allow them to engage
in free telephone calls, file transfers, conference
calling. voice-mail and video calling functionality. There
are additional services offered by Skype that allow users
to Skype-out [call to the standard PSTN services] and
Skype-in [call from PSTN to Skype-enabled devices] at
Many mobile telephones now run Windows derivatives
and Skype can be installed on those devices. The user
can then utilize the mobile operators network to use
This is a major threat to the calling revenue of
Blue Coat's ProxySG family of appliances can recognize
Skype traffic being sent across the network and [working
together with firewalls] the ProxySG appliances can block
Skype, ensuring the mobile operators call revenue is not
Some mobile operators may choose to offer a premium-
rate value-added service where authorized users pay
an additional amount each month to allow them to use
Skype. As the ProxySG appliances can integrate with both
the operators LDAP and RADIUS directories, the operator
can deploy Blue Coat appliances to block Skype for most
users and allow it for users who sign up for the premium-
Operators can provide a web- based interface where users
self-select the Skype-enabled premium-rate service.
If the operator uses the port- blocking capabilities of
firewalls to block the standard IP ports used by Skype.
then the Skype application will try to transmit its data
over TCP port 80 or TCP port 443, commonly used for web
browsing and SSL traffic respectively.
As the traffic over port 80 is not valid HTTP traffic, the
ProxySG can recognize this and block the Skype traffic.
Skype then tries to use port 443, the standard port for
traffic. The ProxySG can be configured to block
all traffic over port 443 that does not contain a valid
In this way, Skype is blocked effectively from the mobile
See our Skype White Paper and Skype Tech Brief for more
detailed explanation of the solution.
Skype is a service that offers free calls worldwide
between Skype-enabled devices.
Most devices enabled to use Skype are PCs, however
mobile 'phones are becoming Skype-enabled at a
There are now more than 250million Skype
Skype is a major threat to the revenue stream of
As more mobile phones becomes Internet-ready, the
threat keeps increasing
Blue Coat can block Skype within Mobile
Operators may choose to embrace Skype and offer a
value-added service that includes Skype
Blue Coat can integrate with LDAP and RADIUS
directories simultaneously to enable the operator to offer
this premium service
Users can be offered a web- based self-select service to
sign up for a contract that allows Skype traffic to pass
across the network.
Blue Coat Systems. Inc. 1.866.30.BCOAT 408.220.2200 Direct 408.220.2250 Fax//
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