Internet DRAFT - draft-netext-pmip-qos-wifi
draft-netext-pmip-qos-wifi
NETEXT WG John Kaippallimalil
INTERNET-DRAFT Huawei
Intended Status: Informational Rajesh S. Pazhyannur
Expires: November 3, 2014 Cisco
Parviz Yegani
Juniper
May 2, 2014
Mapping 802.11 QoS in a PMIPv6 Mobility Domain
draft-netext-pmip-qos-wifi-00
Abstract
This document provides a model for enabling end to end QoS in systems
where there is a 802.11 based wireless system coupled with a PMIPv6
mobility domain consisting a local mobility anchor and mobility
access gateway. This enables QoS policing and labeling of packets in
a consistent manner on the 802.11 link between the MN and the AP as
well as the link between the MAG and the LMA. To enable this, the
document specifies mapping between QoS parameters on the 802.11 link
and the QoS Mobility options in the PMIPv6 domain.
Status of this Memo
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Copyright and License Notice
Copyright (c) 2014 IETF Trust and the persons identified as the
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document authors. All rights reserved.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . . 5
1.2. Definitions . . . . . . . . . . . . . . . . . . . . . . . . 5
1.3. Abbreviations . . . . . . . . . . . . . . . . . . . . . . . 5
2. Mapping 802.11 and PMIP QoS . . . . . . . . . . . . . . . . . 6
2.1. Service Structure and Semantics of 802.11 QoS . . . . . . 6
2.2. Mapping of 802.11 QoS to PMIP QoS Parameters . . . . . . 6
2.2.1. Connection Parameters . . . . . . . . . . . . . . . . . 6
2.2.2. QoS Class . . . . . . . . . . . . . . . . . . . . . . . 7
2.2.3. Bandwidth . . . . . . . . . . . . . . . . . . . . . . . 7
2.3. 802.11 and MAG Admission Control Considerations . . . . . 8
3. Call Flows . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.1. MN Initiated QoS Provisioning . . . . . . . . . . . . . . . 9
3.1.1. MN Initiated QoS Request . . . . . . . . . . . . . . . 9
3.1.2. MN Initiated QoS Release . . . . . . . . . . . . . . . 11
3.2. Network Initiated QoS Provisioning . . . . . . . . . . . . 12
3.2.1. Network Initiated QoS Request . . . . . . . . . . . . . 12
3.2.2. Network Initiated QoS Release . . . . . . . . . . . . . 14
4. Security Considerations . . . . . . . . . . . . . . . . . . . . 16
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 16
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 16
7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 16
7.1. Normative References . . . . . . . . . . . . . . . . . . . 16
7.2. Informative References . . . . . . . . . . . . . . . . . . 16
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 17
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1. Introduction
802.11 networks can currently apply QoS policy by using ALG
(Application Level Gateway) to detect an application (e.g. SIP
signaling) and then install QoS for the corresponding IP flow on the
Wireless LAN Controller (WLC)/ Access Point (AP). However, this is
not a general mechanism and would require ALG or detection of
application level semantics in the access to install the right QoS.
[PMIP-QoS] describes a application neutral procedure to obtain QoS
for PMIPv6 flows and sessions. However, there are differences in
parameters and procedures that need to be mapped between PMIPv6 QoS
and 802.11. PMIPv6 has the notion of QoS for mobility sessions and
flows while in 802.11 these should correspond to QoS for 802.11 data
frames. Parameters in 802.11 QoS do not always have a one-to-one
correspondence in PMIPv6 QoS. Further, 802.11 and PMIP QoS procedures
need to be aligned based on whether QoS setup is triggered by the MN
or pushed by the the network, as well as working with WMM or 802.11aa
mechanisms.
This document provides information on using PMIPv6 QoS parameters for
an MN connection over a 802.11 access network. The recommendations
here allow for dynamic QoS policy information per Mobile Node (MN)
and session to be configured by the 802.11 access network. PMIPv6
QoS signaling between MAG and LMA provisions the per MN QoS policies
in the MAG. In the 802.11 access network modeled here, the MAG is
located at the Access Point (AP)/ Wireless LAN Controller (WLC) .
Figure 1 below provides an overview of the entities and protocols.
+--------+ +-------+
| AAA | | PCF |
+---+----+ +---+---+
| |
| |
+----+ +---+----+ +---+---+
| | 802.11 (WMM, 802.11aa) | | PMIPv6 | |
| MN <------------------------> AP/WLC <==========> LMA |
| | (ADDTS, DELTS) | (MAG) | QoS | |
+----+ +--------+ +-------+
Figure 1: QoS Policy in 802.11 Access
MN and AP/WLC use 802.11 QoS mechanisms to setup admission controlled
flows.
The AP/WLC (MAG) requests QoS policy from the LMA using PMIPv6 QoS
extensions. This document does not exclude various deployments
including those where AP and WLC are separate nodes, or the MAG
control and data planes are separate.
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The LMA provisions QoS policy when the MN initiates QoS requests and
when QoS policy is pushed to the MN. In WMM [WMM 1.2.0], the AP
advertises if admission control is mandatory for an access class.
Admission control for best effort or background access classes is not
recommended. When the MN initiates QoS setup, it uses ADDTS (Add
Traffic Stream) to request QoS for a traffic stream between itself
and the AP, and DELTS (Delete Traffic Stream) to delete that stream.
When the network initiates QoS policy provisioning, 802.11aa
capability is required. The LMA sends QoS policy to the AP/WLC, which
in turn triggers an ADDTS reservation request to the MN.
The parameter mapping recommendations described here support the
procedures by which the 3GPP network provisions QoS per application
dynamically or during authorization of the Mobile Node (MN). However,
the 802.11 procedures described here are not limited to work for just
the 3GPP policy provisioning. If PMIPv6 QoS parameters can be
provisioned on the MAG via mechanisms defined in [PMIP-QoS], the
802.11 procedures can be applied in general for provisioning OoS in a
802.11 network.
PMIPv6 QoS parameters need to be mapped to 802.11 QoS parameters. In
some cases, there is no one-to-one mapping. And in other cases such
as bandwidth, the values received in PMIP should be mapped to the
right 802.11 parameters. This document provides recommendations to
perform QoS mapping between PMIPv6 and 802.11 QoS.
[PMIP-QoS] does not explicitly describe how the QoS signaling and QoS
sub-options map into corresponding signaling and parameters in the
802.11 access network. This mapping and the procedures in the 802.11
network to setup procedures are the focus of this document. The
end-to-end flow spanning 802.11 access and PMIPv6 domain and the QoS
parameters in both segments are described here. Thus, it provides a
systematic way to map the various QoS parameters available in
initial authorization, as well as setup of new sessions (such as a
voice/video call). The mapping recommendations allow for proper
provisioning and consistent interpretation between the various QoS
parameters provided by PMIP QoS, and 802.11.
The rest of the document is organized as follows. Chapter 2 provides
an overview of establishing mobility sessions with no admission
control. These mechanisms are specified in [PMIP QoS] and outlined
here since the mobility session established is the basis for
subsequent admission controlled requests for flows. Chapter 3
describes how end to end QoS with 802.11 admission control is
achieved. The mapping of parameters between 802.11 and PMIP QoS is
described in Chapter 5.
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1.1. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119].
1.2. Definitions
Peak Data Rate
In WMM, Peak Data Rate specifies the maximum data rate in bits
per second. The Maximum Data Rate does not include the MAC and
PHY overheads [WMM 1.2.0].
Mean Data Rate
This is the average data rate in bits per second. The Mean Data
Rate does not include the MAC and PHY overheads [WMM1.2.0]
Minimum Data Rate
In WMM, Minimum Data Rate specifies the minimum data rate in bits
per second. The Minimum Data Rate does not include the MAC and
PHY overheads [WMM 1.2.0].
TSPEC
The TSPEC element in 802.11 contains the set of parameters that
define the characteristics and QoS expectations of a traffic
flow.
TCLAS
The TCLAS element specifies an element that contains a set of
parameters necessary to identify incoming MSDU (MAC Service Data
Unit) that belong to a particular TS (Traffic Stream) [802.11].
1.3. Abbreviations
AAA Authentication Authorization Accounting
AMBR Aggregate Maximum Bit Rate
ARP Allocation and Retention Priority
AP Access Point
DSCP Differentiated Services Code Point
EPC Enhanced Packet Core
GBR Guaranteed Bit Rate
MAG Mobility Access Gateway
MBR Maximum Bit Rate
MN Mobile Node
QCI QoS Class Indicator
QoS Quality of Service
TCLAS Type Classification
TSPEC Traffic Conditioning Spec
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WLC Wireless Controller
2. Mapping 802.11 and PMIP QoS
This section provides an outline of the semantics and mapping of QoS
parameters between 802.11 and PMIP QoS. While PMIP QoS provisions QoS
for IP sessions and flows, 802.11 QoS reservations are made for an
MN's data frames. Similarly, parameters in PMIP QoS and 802.11 do not
have a one-to-one correspondence. The sections below provide
recommendations on mapping of parameters as well as signaling
triggers for the QoS service request.
2.1. Service Structure and Semantics of 802.11 QoS
IEEE 802.11-2012 [802.11-2012] provides an enhancement of the MAC
layer in 802.11 networks to support QoS--EDCA (Enhanced Distributed
Channel Access). EDCA uses a contention based channel access method
to provide differentiated, distributed access using eight different
UPs (User Priorities). EDCA defines four access categories (AC) that
provide support for the delivery of traffic. In EDCA, the random
back-off timer and arbitration inter-frame space is adjusted
according to the QoS priority. Frames with higher priority AC have
shorter random back-off timers and arbitration inter-frame spaces.
Thus, there is a better chance for higher priority frames to be
transmitted. The Wi-Fi Alliance has created a specification referred
to as WMM (Wi-Fi Multimedia) based on above.
The MN uses ADDTS (Add Traffic Specs) to setup QoS for a traffic
stream between itself and the AP, and DELTS to delete that stream. In
WMM [WMM 1.2.0], the AP advertises if admission control is mandatory
for an access class. Admission control for best effort or background
access classes is not recommended. The Wi-Fi Alliance has created a
specification referred to as WMM-AC (Wi-Fi Multimedia Admission
Control) based on the above.
It should be noted that there are no guaranteed or committed
resources in an 802.11 network - only prioritization that gives
better opportunity for frames to compete for a shared medium.
2.2. Mapping of 802.11 QoS to PMIP QoS Parameters
2.2.1. Connection Parameters
TSPEC in 802.11 is used to reserve QoS for a traffic stream (MN MAC,
TS(Traffic Stream) id). The 802.11 QoS reservation is for 802.11
frames associated with an MN's MAC address. TCLAS element with
Classifier 1 (TCP/UDP Parameters) are used to identify a PMIP QoS
flow. There is a one-to-one mapping between the TCLAS defined flow
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and that in Traffic Selector.
+------------------------------+------------------------------+
| MN <--> AP/WLC(802.11) | AP/WLC(MAG) <--> LMA PMIPv6 |
+------------------------------+------------------------------+
| (TCLAS) TCP/UDP IP | Traffic Selector (IP flow) |
| (TCLAS) User Priority | DSCP |
+------------------------------+------------------------------+
Table 1: 802.11 - PMIPv6 QoS Connection mapping
If the MN or AP/WLC is not able to convey flow parameters in TCLAS,
the AP/WLC should use out of band methods to determine the IP flow
for which QoS is requested. This may include higher level connection
setup signaling (e.g., WCS in 3GPP 23.402).
2.2.2. QoS Class
Table 2 contains a mapping between Access Class (WMM AC) and 802.1D
in 802.11 frames, and DSCP in IP data packets. The table also
provides the mapping between Access Class (WMM AC) and DSCP for use
in 802.11 TSPEC and PMIP QoS reservations.
QCI DSCP 802.1D UP WMM AC Example Services
------------------------------------------------------------
1 EF 6(VO) 3 AC_VO conversational voice
2 EF 6(VO) 3 AC_VO conversational video
3 EF 6(VO) 3 AC_VO real-time gaming
4 AF41 5(VI) 2 AC_VI buffered streaming
5 AF31 4(CL) 2 AC_VI signaling
6 AF32 4(CL) 2 AC_VI buffered streaming
7 AF21 3(EE) 0 AC_BE interactive gaming
8 AF11 1(BE) 0 AC_BE web access
9 BE 0(BK) 1 AC_BK e-mail
Table 2: QoS Mapping between QCI/DSCP, 802.1D UP, WMM AC
The MN tags all data packets with DSCP and 802.1D UP corresponding to
the application and the subscribed policy or authorization. The
AP/WLC polices sessions and flows based on the configured QoS policy
values for the MN.
For QoS reservations, TSPEC uses WMM AC values and PMIP QoS uses
corresponding DSCP values in Traffic Selector. 802.11 QoS Access
Class AC_VO, AC_VI are used for QoS reservations. AC_BE, AC_BK should
not be used in reservations.
2.2.3. Bandwidth
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Bandwidth parameters that need to be mapped between 802.11 and PMIP
QoS are shown in Table 3.
Table 3 shows the mapping of bandwidth parameters.
+-------------------------+------------------------------+
| MN <--> AP/WLC(802.11) | AP/WLC(MAG) <--> LMA PMIPv6 |
+-------------------------+------------------------------+
| Mean Data Rate, DL | Guaranteed-DL-Bit-Rate |
| Mean Data Rate, UL | Guaranteed-UL-Bit-Rate |
| Peak Data Rate, DL | Aggregate-Max-DL-Bit-Rate |
| Peak Data Rate, UL | Aggregate-Max-UL-Bit-Rate |
+-------------------------+------------------------------+
Table 3: Bandwidth Parameters for Admission Controlled Flows
In PMIP QoS, services using a sending rate smaller than or equal to
Guaranteed Bit Rate (GBR) can in general assume that congestion
related packet drops will not occur [TS 23.203]. If the rate offered
by the service exceeds this threshold, there are no guarantees
provided. 802.11 radio networks do not offer such a guarantee, but
[WMM 1.2.0] notes that the application (service) requirements are
captured in TSPEC by the MSDU (MAC Service Data Unit) and Mean Data
Rate. The TSPEC should contain Mean Data Rate and it is recommended
that it be mapped to the GBR parameters, Guaranteed-DL-Bit-Rate and
Guaranteed-UL-Bit-Rate in PMIP QoS.
802.11 TSPEC requests do not require all fields to be completed. [WMM
1.2.0] specifies a list of TSPEC parameters that are required in the
specification. Peak Data Rate is not required in WMM, however for MNs
and APs that are capable of specifying the Peak Data Rate, it should
be mapped to MBR (Maximum Bit Rate) in PMIP QoS. The AP/WLC should
use the MBR parameters, Aggregate-Max-DL-Bit-Rate and Aggregate-Max-
UL-Bit-Rate to police these flows on the backhaul segment between MAG
and LMA.
During the QoS reservation procedure, if the MN requests Mean Data
Rate, or Peak Data Rate in excess of values authorized in PMIP QoS,
the AP/WLC should deny the request in ADDTS Response. The AP/WLC may
set the reject cause code to REJECTED_WITH_SUGGESTED_CHANGES and send
a revised TSPEC with Mean Data Rate and Peak Data Rate set to
acceptable GBR and MBR respectively in PMIP QoS.
2.3. 802.11 and MAG Admission Control Considerations
Flows and sessions that do not need QoS reservation have no signaling
or equivalent mapping in 802.11. These sessions and flows are policed
by the AP/WLC to ensure that QoS policy obtained initially (during MN
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authorization) or dynamically over PMIP QoS is not exceeded by the
MN.
All connection sessions of the MN with no explicit reservation should
not in total exceed Per-MN-Agg-Max-DL-Bit-Rate and Per-MN-Agg-Max-UL-
Bit-Rate in the downlink and uplink directions respectively. The non-
admission controlled flows of a single connectivity session of an MN
should not exceed Per-Session-Agg-Max-DL-Bit-Rate and Per-Session-
Agg-Max-UL-Bit-Rate in the downlink and uplink directions
respectively.
When there are insufficient resources in the radio network, the
AP/WLC may preempt existing calls based on the Preemption-Capability
of a new call and Preemption-Vulnerability of established calls.
Parameter Allocation-Retention-Priority and sub fields of Priority,
Preemption-Capability and Preemption-Vulnerability are used as
defined in [RFC 7222]. If the AP/WLC determines that an established
flow with reserved resources should be released, the AP/WLC should
inform the MN using ADDTS (802.11aa) and signal the LMA with a
revised QoS reservation in PBU/PBA.
3. Call Flows
There are two main types of interaction possible to provision QoS for
flows that require admission control - one where the MN initiates the
QoS request and the network provisions the resources. The second is
where the network provisions resources as a result of PMIP QoS
request. In the second scenario, if the MN supports 802.11aa, the
network can push the QoS configuration to the MN. If the MN only
supports WMM QoS, then MN requests for QoS for the 802.11 segment and
the MAG provisions based on QoS already provisioned for the MN.
3.1. MN Initiated QoS Provisioning
3.1.1. MN Initiated QoS Request
This procedure outlines the case where the MN is configured to start
the QoS signaling. In this case, the MN sends an ADDTS request
indicating the QoS required for the flow. The AP/WLC (MAG) obtains
the corresponding level of QoS to be granted to the flow by PMIPv6
PBU/PBA sequence with QoS options with the LMA. Details of the QoS
provisioning for the flow are described below.
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+--------+
+----+ | AP/WLC | +-------+
| MN | | (MAG) | | LMA |
+-+--+ +---+----+ +---+---+
| | |
+-------------------------------------------------------------+
| [0] establish connection session to mobile network |
+-------------------------------------------------------------+
| | |
+-------------+ | |
|upper layer | | |
|notification | | |
+-+-+-+-+-+-+-+ | |
| | |
| ADDTS Request (TCLAS,TSPEC) | |
|---------------------------->| PBU(QoS options)[2] |
| [1] |-------------------->| QoS Policy
| |PBA (QoS option) [3] |<--------->
| ADDTS Response(TCLAS,TSPEC) |<--------------------|
|<----------------------------| |
| [4] | |
Figure 3: MN initiated QoS setup
[0] The MN establishes a connectivity session as described in [RFC
7222], section 3.1, MAG-initiated QoS service request, steps 1-
4. At this point, a connection with PMIPv6 tunnel is established
to the LMA. This allows the MN to start application level
signaling.
[1] The trigger for MN to request QoS is an upper layer
notification. This may be the result of end-to-end application
signaling and setup procedures (e.g. SIP)
Since the MN is configured to start QoS signaling, it sends an
ADDTS request with TSPEC and TCLAS identifying the flow for
which QoS is requested. The TSPECs for both uplink and downlink
in this request should contain the Mean Data Rate and and may
contain Peak Data Rate.
[2] If there are sufficient resources at the AP/WLC to satisfy the
request, the MAG (AP/WLC sends a PBU with QoS options,
operational code ALLOCATE and Traffic Selector identifying the
flow. The Traffic selector is derived from the TCLAS to identify
the flow requesting QoS. 802.11 QoS parameters in TSPEC are
mapped to PMIPv6 parameters. The mapping of TCLAS to PMIPv6 is
shown in Table 1. TSPEC parameter mapping is shown in Table 3.
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[3] The LMA obtains the authorized QoS for the flow and responds to
the MAG with operational code set to RESPONSE. Mapping of PMIPv6
to 802.11 TCLAS is shown in Table 1, TSPEC parameters in Table
3.
Reserved bandwidth for flows are accounted separately from the
non-reserved session bandwidth. The Traffic Selector identifies
the flow for which the QoS reservations are made.
[4] The AP/WLC (MAG) provisions the corresponding QoS and replies
with ADDTS Response containing authorized QoS in TSPEC and flow
identification in TSPEC.
The AP/WLC polices these flows according to the QoS
provisioning.
3.1.2. MN Initiated QoS Release
QoS resources reserved for a session are released on completion of
the session. When the application session completes, the policy
server, or the MN may signal for the release of resources. In this
use case, the network initiates the release of QoS resources.
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+--------+
+----+ | AP/WLC | +-------+
| MN | | (MAG) | | LMA |
+-+--+ +---+----+ +---+---+
| | |
+-------------------------------------------------------------+
| [0] Establishment of application session |
| and reservation of QoS resources |
| |
| ( Session in progress) |
| |
| Release of application session |
+-------------------------------------------------------------+
| | |
| DELTS Request | |
| (TS INFO)[1] | |
|----------------------->| |
| DELTS Response | |
| (TS INFO)[2] | |
|<-----------------------| |
| |PBU(QoSx,DE-ALLOC)[3]
| |------------------->| Policy Update
| |PBA(QoSx,RESPONSE)[4]<------------>
| |<-------------------|
| | |
Figure 6: Network initiated QoS resource release
[0] The MN establishes and reserves QoS resources as in use cases A,
B or C.
When the application session terminates, the MN prepares to
release QoS resources.
[1] MN releases its own internal resources and sends a DELTS Request
to the AP/WLC with TS (Traffic Stream) INFO.
[2] AP/WLC receives the DELTS request, releases local resources and
responds to MN with a DELTS response.
[3] AP/WLC (MAG) initiates a PBU with Traffic Selector constructed
from TCLAS and PMIPv6 QoS parameters from TSPEC (QoSx).
[4] LMA receives the PBU, releases local resources and informs
policy server. The LMA then responds with a PBA.
3.2. Network Initiated QoS Provisioning
3.2.1. Network Initiated QoS Request
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When the MN is provisioned to wait for QoS configuration from the
network, QoS policy configuration is triggered by PMIP QoS requests
from LMA to MAG. This use case illustrates how an MN and 802.11
network that support 802.11aa can provision QoS to flows of the MN
that when the policy server pushes the reservation request.
+--------+
+----+ | AP/WLC | +-------+
| MN | | (MAG) | | LMA |
+-+--+ +---+----+ +---+---+
| | |
+----------------------------------------------------------------+
| [0] establish connection session to mobile network |
+----------------------------------------------------------------+
| | |
| | | Policy update
| |UPN(QoS option)[2]|<-------------
| ADDTS Reserve Request |<-----------------| [1]
| (TCLAS, TSPEC)[3] | |
|<----------------------------| |
| ADDTS Reserve Response | |
| (TCLAS, TSPEC)[4] | |
|---------------------------->| |
| |UPA(QoS option)[5]|
| |----------------->|
| | |
Figure 4: Network initiated QoS setup with 802.11aa
[0] The MN sets up best effort connectivity session as described in
Case A. This allows the MN to perform application level
signaling and setup.
[1] The policy server sends a QoS reservation request to the LMA.
This is usually sent in response to an application that requests
the policy server for higher QoS for some of its flows.
The LMA reserves resources for the flow requested.
[2] LMA sends PMIP UPN (Update Notification) to the MAG with QoS
parameters for the flow for which the LMA reserved resources in
step [1]. In UPN, the operational code in QoS option is set to
ALLOCATE and the Traffic Selector identifies the flow for QoS.
The LMA QoS parameters include Guaranteed-DL-Bit-
Rate/Guaranteed-UL-Bit-Rate and Aggregate-Max-DL-Bit-
Rate/Aggregate-Max-UL-Bit-Rate for the flow. In networks like
3GPP, the reserved bandwidth for flows are accounted separately
from the non-reserved session bandwidth.
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[3] If there are sufficient resources to satisfy the request, the
AP/WLC (MAG) sends an ADDTS Reserve Request (802.11aa)
specifying the QoS reserved for the traffic stream including
TSPEC and TCLAS element mapped from PMIP QoS Traffic Selector to
identify the flow.
PMIPv6 parameters are mapped to TCLAS (Table 1) and TSPEC (Table
3).
If there are insufficient resources at the AP/WLC, the MAG will
not send and ADDTS message and will continue processing of step
[5].
[4] MN accepts the QoS reserved in the network and replies with
ADDTS Reserve Response.
[5] The MAG (AP/WLC) replies with UPA confirming the acceptance of
QoS options and operational code set to RESPONSE. The AP/WLC
police flows based on the new QoS.
If there are insufficient resources at the AP/WLC, the MAG sends
a response with UPA status code set to
CANNOT_MEET_QOS_SERVICE_REQUEST.
3.2.2. Network Initiated QoS Release
QoS resources reserved for a session are released on completion of
the session. When the application session completes, the policy
server, or the MN may signal for the release of resources. In this
use case, the network initiates the release of QoS resources.
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+--------+
+----+ | AP/WLC | +-------+
| MN | | (MAG) | | LMA |
+-+--+ +---+----+ +---+---+
| | |
+-------------------------------------------------------------+
| [0] Establishment of application session |
| and reservation of QoS resources |
| |
| ( Session in progress) |
| |
| Release of application session |
+-------------------------------------------------------------+
| | | Policy update
| |UPN(QoSx,DE-ALLOC)[2]<--------------
| |<-------------------| [1]
| |UPA(QoSx,RESPONSE)[3]
| |------------------->|
| DELTS Request | |
| (TS INFO)[4] | |
|<-----------------------| |
| DELTS Response | |
| (TS INFO)[5] | |
|----------------------->| |
| | |
Figure 6: Network initiated QoS resource release
[0] The MN establishes and reserves QoS resources as in use cases A,
B or C.
When the application session terminates, the policy server
receives notification that the session has terminated.
[1] LMA receives a policy update indicating that QoS for flow (QoSx)
should be released. The LMA releases local resources associated
with the flow.
[2] LMA sends a UPN with QoS options - Traffic Selector field
identifying the flow for which QoS resources are to be released,
and operation code set to DE-ALLOCATE. No additional LMA QoS
parameters are sent.
[3] MAG replies with UPA confirming the acceptance and operation
code set to RESPONSE.
[4] AP/WLC (MAG) releases local QoS resources associated with the
flow. AP/WLC derives the corresponding 802.11 Traffic Stream
from the PMIPv6 Traffic Selector. The AP sends a DELTS Request
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with TS INFO identifying the reservation.
[5] MN sends DELTS Response confirming release.
Since the MN has completed the session, it may send a DELTS to
explicitly request release QoS resources at AP. If the AP and MN
are 802.11aa capable, the release of resources may also be
signaled to the MN.
4. Security Considerations
This document describes mapping of PMIP QoS parameters to IEEE 802.11
QoS parameters. No security concerns need to be addressed as a result
of this mapping.
5. IANA Considerations
No IANA assignment of parameters are required.
6. Acknowledgements
The authors of this document thank the NetExt Working Group for the
valuable feedback to different versions of this specification. In
particular, the authors wish to thank Sri Gundavelli, Rajeev, Koodli,
Georgios Karagianis, Kent Leung, Marco Liebsch, Basavaraj Patil,
Pierrick Seite, Hidetoshi Yokota for their suggestions and valuable
input. The authors also thank George Calcev, Mirko Schramm, Mazin
Shalash and Marco Spini for detailed input on parameters and
scheduling in 802.11 and 3GPP radio networks.
7. References
7.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC7222] Liebsch, et al., "Quality of Service Option for Proxy
Mobile IPv6", draft-ietf-netext-pmip6-qos-11, Feb 2014.
[RFC 5226] Narten, T. and H. Alvestrand, "Guidelines for Writing
an IANA Considerations Section in RFCs", BCP 26, RFC
5226, May 2008.
7.2. Informative References
[802.11-2012] 802.11-2012 - IEEE Standard for Information Technology-
-Telecommunications and information exchange between
systems Local and metropolitan area networks--Specific
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requirements Part 11: Wireless LAN Medium Access
Control (MAC) and Physical Layer (PHY) Specifications
[WMM 1.2.0] Wi-Fi Multimedia Technical Specification (with WMM-
Power Save and WMM-Admission Control) Version 1.2.0
[802.11aa] Wireless LAN Medium Access Control (MAC) and Physical
Layer (PHY) Specification, Amendment 2: MAC
Enhancements for Robust Audio Video Streaming, IEEE
802.11aa-2012.
[GSMA-IR34] Inter-Service Provider Backbone Guidelines 5.0, 22
December 2010
[TS23.402] Architecture Enhancements for non-3GPP accesses(Release
12), 3GPP TS 23.402, V12.2.0 (2013-09).
[TS23.203] Policy and Charging Control Architecture, Release 11,
3GPP TS 23.203, V11.2.0 (2011-06).
[RFC 2211] Wroclawski, J., "Specification of the Controlled Load
Quality of Service", RFC 2211, September 1997.
[RFC 2212] Shenker, S., Partridge, C., and R. Guerin,
"Specification of Guaranteed Quality of Service", RFC
2212, September 1997.
[RFC 2216] Shenker, S., and J. Wroclawski, "Network Element QoS
Control Service Specification Template", RFC 2216,
September 1997.
Authors' Addresses
John Kaippallimalil
5340 Legacy Drive, Suite 175
Plano, Texas 75024
E-Mail: john.kaippallimalil@huawei.com
Rajesh Pazhyannur
170 West Tasman Drive
San Jose, CA 95134
E-Mail: rpazhyan@cisco.com
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Parviz Yegani
1194 North Mathilda Ave.
Sunnyvale, CA 94089-1206
E-Mail: pyegani@juniper.net
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