Cisco ASR 5000 Series, Обзор продукта

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Serving GPRS Support Node (SGSN) Overview
▀ Features and Functionality - Basic
▄ Cisco ASR 5000 Series Product Overview
OL-22938-02
Short Message Service CDRs
SGSN supports following CDRs for SMS related charging:
SMS-Mobile Originated CDRs (SMS-MO-CDRs)
SMS Mobile Terminated CDRs (SMS-MT-CDRs)
These charging records are generated by the SGSN‘s Short Message Service component. They contain attributes as
defined in 3GPP TS 32.215 v5.9.0.
Overcharging Protection
In releases 9.0 and higher, Overcharging Protection enables the SGSN to avoid overcharging the subscriber if/when a
loss of radio coverage (LORC) occurs.
When a mobile is streaming or downloading files from external sources (for example, via a background or interactive
traffic class) and the mobile goes out of radio coverage, the GGSN is unaware of such loss of connectivity and continues
to forward the downlink packets to the SGSN.
Previously, upon loss of radio coverage (LORC), the SGSN did not perform the UPC procedure to set QoS to 0kbps, as
it does when the traffic class is either streaming or conversational. Therefore, when the SGSN did a Paging Request, if
the mobile did not respond the SGSN would simply drop the packets without notifying the GGSN; the G-CDR would
have increased counts but the S-CDR would not, causing overcharges when operators charged the subscribers based on
the G-CDR.
Now operators can accommodate this situation, they can configure the SGSN to set QoS to 0kbps upon detecting the
loss of radio coverage. The overcharging protection feature relies upon a proprietary private extension to GTP LORC
Intimation IE messages. This LORC Intimation IE is included in UPCQ, DPCQ, DPCR and SGSN Context Response
GTP messages. One of the functions of these messages, notify the GGSN to prevent overcharging.
The following table summarizes the SGSN's actions when radio coverage is lost or regained and LORC overcharging
protection is enabled.
Table 86. Overcharging Protection - SGSN Actions
Condition Triggered by SGSN Action LORC Intimation IE -
private extension payload
Loss of radio coverage
(LORC) RNC sends Iu release request with
cause code matching configured
value Send UPCQ to GGSN
Start counting unsent
packets/bytes
Stop forwarding packets in
downlink direction No payload
Mobile regains coverage
in same SGSN area MS/SGSN Send UPCQ to GGSN
Stop counting unsent
packets/bytes
Stop discarding downlink
packets New LORC state and
unsent packet/byte counts