для Cisco Cisco Packet Data Gateway (PDG)
ePDG Bearer Duration KPIs
ePDG supports QCI based bearer duration information display at more granular leval to enable customers to
Monitor VoWiFi dedicated bearers.
Monitor VoWiFi dedicated bearers.
For more information on show subscriber statistics and for show session duration commands refer CLI
Reference Guide.
Reference Guide.
Data Buffering Support for DL Packets Before Session Establishment
To establish ePDG call once the PGW sends the create session response message to ePDG the call setup is
complete at PGW and Downlink traffic may come. However on ePDG processing of create session response
and setting up of IPsec tunnel may take small duration, so it is required that before bearer establishment and
IPsec tunnel establishment is completed ePDG should have capability to buffer the data. In case of handover
especially when the LTE bearer is torn down after sending create session response the downlink traffic shall
be sent over the WLAN so this becomes even more important to buffer data on ePDG avoiding any traffic
loss.
complete at PGW and Downlink traffic may come. However on ePDG processing of create session response
and setting up of IPsec tunnel may take small duration, so it is required that before bearer establishment and
IPsec tunnel establishment is completed ePDG should have capability to buffer the data. In case of handover
especially when the LTE bearer is torn down after sending create session response the downlink traffic shall
be sent over the WLAN so this becomes even more important to buffer data on ePDG avoiding any traffic
loss.
3GPP standards section 8.6.2 "Handover from 3GPP access to untrusted Non-3GPP IP Access with GTP on
S2b" indicates that traffic can come from PGW to ePDG before even the session setup is done at ePDG (during
the processing of create session response at ePDG).
S2b" indicates that traffic can come from PGW to ePDG before even the session setup is done at ePDG (during
the processing of create session response at ePDG).
Downlink DSCP Marking(SWu)
The ESP IP header of the downlink packet in SWu interface sent out of ePDG has the TOS value copied from
the inner IP payload of the ESP packet. But as per the customer requirement the TOS value should be taken
from the configuration or GTPU IP header received on S2B side.
the inner IP payload of the ESP packet. But as per the customer requirement the TOS value should be taken
from the configuration or GTPU IP header received on S2B side.
Functional description
The ePDG marks the DSCP value in the ESP IP header while sending out in the SWu interface(both IPv4 and
IPv6) based on the following order of priority:
IPv6) based on the following order of priority:
1
DSCP Configuration per QCI
• Use command qci num downlink encaps-header dscp-marking dscp-marking-value to configure
marking of specific DSCP in downlink direction per QCI.
2
From GTPU header received from PGW.
Download DSCP marking feature is backward compatible, where the Inner-GTP IP packet(S2B) DSCP value
should be copied to the outer ESP IP packet(SWu). Use command qci num downlink encaps-header
copy-inner dscp-marking-value to enable copying of DSCP value from inner-gtp-ip packet header(S2B) to
the outer-esp header(SWu)
should be copied to the outer ESP IP packet(SWu). Use command qci num downlink encaps-header
copy-inner dscp-marking-value to enable copying of DSCP value from inner-gtp-ip packet header(S2B) to
the outer-esp header(SWu)
DSCP marking is supported in different platforms like ASR5000, ASR5500 and VPC-Si/Di.
ePDG Administration Guide, StarOS Release 19
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Evolved Packet Data Gateway Overview
ePDG Bearer Duration KPIs