A custom-designed device might be connected to
such an unused port of the PSC and deliver an optical signal to a traffic analyzer,
thereby providing access to subscriber and system sensitive data. However, progress
in PSC packaging technology currently prevents this eavesdropping method by applying
so-called secure packaging, where only one trunk port and a predefined number of
drop section ports are available, while others are hidden in a hermetic casing. Access to
other ports is disabled, and typically, device destruction is required to open the casing
if attempting to gain unauthorized access to the upstream channel signal. Figure 7.8
presents an example of a modern PSC module in a secure casing, with one input and a
predefined number of output ports.
Figure 7.8 (a) Actual PSC unit with secure casing and (b) its internal structure
Splice
1?—2 C.
50/50
Coupler housing
Output
Input
(a) (b)
Passive Optical Networks (PONs) 189
Denial-of-Service in EPONs A denial-of-service (DoS) attack causes loss of standard
services observed by all registered and active subscribers and potential loss of network
connectivity if the network equipment is under attack, or severe service quality deterioration
if only one local machine is subject to such an intrusion.
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