Transcript Mobility Session Suspend IETF-75

NetExt WG
IETF-75
Mobility Session Suspend
Ahmad Muhanna, et al.
Background
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In evolved network architecture which uses Proxy MIPv6 for network
based mobility, voice call using IMS MAY not be supported.
When a user have a proxy MIP6 session and receives a voice call, MN
usually falls back to a legacy CS network.
While the MN is attached to the CS network, it is NOT listening to the
data traffic coming over the PMIP6 mobility session from the Mobile
Access Gateway.
MAG needs to drop all downlink data traffic to avoid MN paging and
the termination of the mobile node mobility session.
A mechanism is needed to keep the data session (i.e., suspend) to
avoid reestablishing the PMIP6 data session one more time.
Allowing the MAG to drop the MN downlink traffic without informing the
LMA causes the LMA and the MAG to maintain different states of the
MN session.
In addition, when billing is collected on the LMA and the MAG, different
billing is always expected and error is introduced in the billing system.
An IETF based solution is required to avoid an SDO specific solution.
USECASES
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Any evolved packet based wireless network
solution which uses PMIP6 for IP mobility
while NOT having an IP based voice solution
deployed.
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3GPP2, HRPD with 1x CS Fallback.
3GPP, LTE with CS Fallback
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WiMAX with CS Fallback
Proposal
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When the MAG receives an indication of the MN mobility session
suspension, MAG informs the LMA via a PBU message with Mobility
Session Suspend (MSS) option included and S-Flag set.
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MAG update the MN Binding in the BUL and the MN routing entry to
start dropping all downlink traffic being sent to the mobile node.
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After processing PBU with MSS option included, LMA updates the
MN BCE and the MN routing entry to drop all downlink traffic.
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When the MN session resumes regular data activities, MAG sends a
PBU with MSS option included and the Suspend flag cleared.
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This proposal keeps the MAG and the LMA synchronized w.r.t. the
MN mobility session state.
Mobility Session Suspend Option
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MAG include MSS option in PBU with the S-Flag Set to indicate
mobility session suspend starts.
After MSS is exchanged between MAG and LMA, MN downlink
traffic is dropped at the LMA.
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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Type
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Length
|S|
Reserved
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type
TBD
Length 2
S-Flag : 1 : Session Suspend
0 : Session Resume
Mobility Session Suspend/Resume
MN
MAG
Voice Call Arrives
Action: Suspend
LMA
PBU with MSS
S-Flag set
Action: Suspend
• RESUME
PBA with MSS
S-Flag set
PBU with MSS
S-Flag Clear
PBA with MSS
S-Flag Clear
• RESUME
Questions & Comments?
What is Next?
• Add Mobility Session Suspend to NetExt Charter