The ADC in-line service
works in conjuction with the following products:
Detecting P2P protocols
requires recognizing, in real time, some uniquely identifying characteristic
of the protocols. Typical packet classification only requires information
uniquely typed in the packet header of packets of the stream(s)
running the particular protocol to be identified. In fact, many
P2P protocols can be detected by simple packet header inspection. However,
some P2P protocols are different, preventing detection in the traditional
manner. This is designed into some P2P protocols to purposely avoid
detection. The creators of these protocols purposely do not publish
specifications. A small class of P2P protocols is stealthier and
more challenging to detect. For some protocols, no set of fixed
markers can be identified with confidence as unique to the protocol.
Operators care about
P2P traffic because of the behavior of some P2P applications (for example,
Bittorrent, Skype, and eDonkey). Most P2P applications can hog the
network bandwidth such that 20% ADC users can generate
as much traffic as generated by the rest 80% non-ADC users.
This can result into a situation where non-ADC users may not get
enough network bandwidth for their legitimate use because of excess
usage of bandwidth by the ADC users. Network operators need to have
dynamic network bandwidth / traffic management functions
in place to ensure fair distributions of the network bandwidth among
all the users. And this would include identifying P2P traffic in
the network and applying appropriate controlling functions to the
same (for example, content-based premium billing, QoS modifications,
and other similar treatments).
The Application Detection
and Control technology makes use of innovative and highly accurate
protocol behavioral detection techniques. In order to ensure its
effectiveness, the ADC continually supports detection of newer protocols
and versions. For more information on the supported protocols and
applications, refer to the Peer-to-Peer Protocol and Application Detection
Support appendix in this guide.
ADC supports statistics
reporting and postpaid charging policies. Per-protocol statistics
via bulkstats and via report records including:
- UDR types: Summarizing
data usage for a given content type
- EDR types: Specific
to a particular event
- e-GCDRs: Specific to
3GPP
Upon detection of a
P2P protocol for a particular flow, one of the following actions
can be applied:
- Blocking P2P traffic—blocking
protocol(s) and discarding traffic
- Bandwidth policing—limiting
the bandwidth, applied per PDP context per P2P application type
- Flow policing—limiting
the number of simultaneous P2P flows
- QoS support—including
policing
- TOS marking—applied
per P2P protocol type
- Prepaid and postpaid
ADC content-based billing
- Statistics reporting—analyzing
per-protocol statistics using bulkstats