Internet DRAFT - draft-xia-nvo3-vxlan-qosmarking
draft-xia-nvo3-vxlan-qosmarking
Network Working Group F. Xia
Internet-Draft B. Sarikaya
Intended status: Experimental Huawei Technologies Co., Ltd.
Expires: September 6, 2015 S. Fan
China Telecom
March 5, 2015
Quality of Service Marking and Framework in Overlay Networks
draft-xia-nvo3-vxlan-qosmarking-04.txt
Abstract
Overlay networks such as The Virtual eXtensible Local Area Network
enable multiple tenants to operate in a data center. Each tenant
needs to be assigned a priority group to prioritize their traffic
using tenant based quality of service marking. Also, cloud carriers
wish to use quality of service to differentiate different
applications, i.e. legacy, traffic based marking. For these
purposes, Quality of Service bits are assigned in the Virtual
eXtensible Local Area Network outer Ethernet header. How these bits
are assigned and are processed in the network are explained in
detail. Also the document presents a quality of service framework
for overlay networks such as Virtual eXtensible Local Area Network.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on September 6, 2015.
Copyright Notice
Copyright (c) 2015 IETF Trust and the persons identified as the
document authors. All rights reserved.
Xia, et al. Expires September 6, 2015 [Page 1]
Internet-Draft Quality of Service Marking March 2015
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Problem Statement . . . . . . . . . . . . . . . . . . . . . . 3
4. QoS Marking Schemes in VXLAN . . . . . . . . . . . . . . . . 4
4.1. Tenant Based Marking . . . . . . . . . . . . . . . . . . 5
4.2. Application Based Marking . . . . . . . . . . . . . . . . 6
4.3. QoS Bits in Outer IP Header . . . . . . . . . . . . . . . 6
5. Quality of Service Operation at VXLAN Decapsulation Point . . 7
6. Quality of Service Operation at VXLAN Encapsulation Point . . 7
7. QoS processing for VXLAN outer IP header . . . . . . . . . . 8
8. Security Considerations . . . . . . . . . . . . . . . . . . . 9
9. IANA considerations . . . . . . . . . . . . . . . . . . . . . 9
10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 9
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 9
11.1. Normative References . . . . . . . . . . . . . . . . . . 9
11.2. Informative References . . . . . . . . . . . . . . . . . 10
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 10
1. Introduction
Data center networks are being increasingly used by telecom operators
as well as by enterprises. An important requirement in data center
networks is multitenancy, i.e. multiple tenants each with their own
isolated network domain. Virtual eXtensible Local Area Network
(VXLAN) is a solution that is gaining popularity in industry
[RFC7348]. VXLAN overlays a Layer 2 network over a Layer 3 network.
Each overlay is identified by the VXLAN Network Identifier (VNI).
VXLAN tunnel end point (VTEP) can be hosted at the the hypervisor on
the server or higher above in the network. VXLAN encapsulation with
a UDP header is only known to the VTEP, the Virtual Machines (VM)
never sees it.
It should be noted that in this document, VTEP plays the role of the
Network Virtualization Edge (NVE) according to NVO3 architecture for
overlay networks like VXLAN or NVGRE defined in [I-D.ietf-nvo3-arch].
Xia, et al. Expires September 6, 2015 [Page 2]
Internet-Draft Quality of Service Marking March 2015
NVE interfaces the tenant system underneath with the L3 network
called the Virtual Network (VN).
Since VXLAN allows multiple tenants to operate, data center operators
are facing the problem of treating their traffic. There is interest
to provide different quality of service to the tenants based on their
service level agreements, i.e. tenant-based QoS.
Cloud carriers have interest in different quality of service to
different applications such as voice, video, network control
applications, etc. In this case, quality of service marking can be
done using deep packet inspection (DPI) in order to detect the type
of application in each packet, i.e. application based QoS.
In this document, we develop Quality of Service marking solution for
VXLAN as part of the Quality of Service framework for overlay multi-
tenant networks as such it complements VXLAN architecture defined in
[RFC7348]. The solution is compatible with IP level Differentiated
Services model or diffserv described in [RFC2474] and [RFC2475].
Configuration guidelines are described in [RFC4594]. Diffserv
interconnection classes and interconnection practice are described in
[I-D.geib-tsvwg-diffserv-intercon].
2. 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 [RFC2119]. The
terminology in this document is based on the definitions in
[RFC7348].
3. Problem Statement
In an overlay network such as VXLAN network multiple tenants are
supported. There is interest in assigning different priority to each
tenant's traffic based on the premium that tenant pays, etc. In
another words, cloud carriers would like to categorize tenants into
different traffic classes such as diamond, gold, silver and bronze
classes.
Cloud carriers wish to categorize the traffic based on the
application such as voice, video, etc. Based on the type of the
application different traffic classes may be identified and different
priority levels can be assigned to each.
In order to do these, quality of service marking is needed in the
overlay network.
Xia, et al. Expires September 6, 2015 [Page 3]
Internet-Draft Quality of Service Marking March 2015
The solution developed in this document is based on the Network
Virtualization Edge (NVE) to do the marking at the encapsulation
layer. The marking, especially the tenant based QoS marking has to
be done when the frames are introduced by the virtual machines (VM)
because it is the encapsulation layer that adds the tenant
identification, e.g. VXLAN Network Identifier (VNI) to each frame
coming from the VMs. Because of this tenant based Quality of Service
marking SHOULD be done at the encapsulation layer.
4. QoS Marking Schemes in VXLAN
Three bits are reserved in VXLAN Outer Ethernet Header's C-Tag 802.1Q
field/VLAN Tag Information field's priority code point (PCP) field
shown as QoS-flag in Figure 1.
Three bits called QoS-flag are reserved to indicate the quality of
service class that this packet belongs. These bits will be assigned
according to the type of traffic carried in this flow, e.g. video,
voice, critical application, etc. These assignments in relation to
IP level Differentiated Services model, diffserv bits or DS field,
are discussed in Section 7.
0 1 2 3
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |Q o S| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: QoS Flag
Priority code point bits are assigned as follows in IEEE 802.1p
[IEEE802.1D]:
001 - BK or background traffic
000 - BE or best effort traffic
010 - EE or Excellent Effort
011 - CA or Critical Applications
100 - VI or Video
101 - VO or Voice
110 - IC or Internetwork Control
Xia, et al. Expires September 6, 2015 [Page 4]
Internet-Draft Quality of Service Marking March 2015
111 - NC or Network Control
'111' has the highest priority while '001' has the lowest, for
example, video traffic has higher priority than web surfing which is
best effort traffic.
IEEE 802.1p [IEEE802.1D] based PCP marking is supported by most
switches currently deployed that have the QoS capabilities.
We propose two different mappings to make use of the QoS field,
tenant based marking or application based marking. Both of these
markings are compatible with IEEE 802.1p PCP marking as well as the
class selector codepoints defined by diffserv.
4.1. Tenant Based Marking
Tenant based marking is based on tenancy priorities. The cloud
carrier categorizes its tenants into different groups such as
diamond, gold, silver, bronze, standard and so on. All traffic for a
diamond tenant has a high priority to be forwarded regardless of
application types. The below is the mapping proposed in this
document.
001 - Reserved
000 - Standard
010 - Bronze
011 - Silver
100 - Gold
101 - Diamond
110 - Emergency
111 - Reserved
The sender SHOULD assign bits 16-18 with bits assigned values as
above if the quality of service treatment is needed on this packet.
The sender SHOULD assign the same bit pattern to all the packets of
the same tenant, i.e. the same VNI value.
Xia, et al. Expires September 6, 2015 [Page 5]
Internet-Draft Quality of Service Marking March 2015
4.2. Application Based Marking
This marking is based on application priorities. NVE uses some
mechanism such as Deep Packet Inspection (DPI) to identify
application types, and fills in the QoS field based on the identified
application types. The below is a possible mapping.
001 - Reserved
000 - ftp/email
010 - Facebook, Twitter, Social Media
011 - Instant Message
100 - video
101 - voice
110 - High Performance computation
111 - Reserved
The sender SHOULD assign bits 16-18 with bits assigned values as
above if the quality of service treatment is needed on this packet.
The sender SHOULD assign the same bit pattern to all the packets of
the same flow.
4.3. QoS Bits in Outer IP Header
Outer IPv4 header in VXLAN has type of service (TOS) field of 8 bits.
Outer IPv6 header is VXLAN has traffic class field of 8 bits.
In case virtual machines are differentiated services capable, inner
IP header contains per hop behavior (PHB) settings inline with
diffserv RFCs. VXLAN NVE SHOULD copy inner IP header QoS bits into
outer IP header bits.
In case virtual machines are not differentiated services capable,
outer IP header QoS bits MUST be assigned by VXLAN NVE. VXLAN NVE
SHOULD assign one of the class selector (CS) codepoints with value
'xxx000' corresponding to the marking explained above if the packet
is a unicast packet. For more details, see Section 7.
Xia, et al. Expires September 6, 2015 [Page 6]
Internet-Draft Quality of Service Marking March 2015
5. Quality of Service Operation at VXLAN Decapsulation Point
There are two types of VXLAN packets receivers, that is, a VXLAN
enabled NVE or a VXLAN gateway [I-D.sarikaya-nvo3-proxy-vxlan].
When the VXLAN enabled NVE receives the packet, it decapsulates the
packet and delivers it downstream to a corresponding VM. If there
are multiple packets to be processed, packets with high priority
(that is higher QoS value) should be processed first.
The QoS operation is different for the VXLAN gateway processing. The
gateway which provides VXLAN tunnel termination functions could be
ToR/access switches or switches higher up in the data center network
topology. For incoming frames on the VXLAN connected interface, the
gateway strips out the VXLAN header and forwards to a physical port
based on the destination MAC address of the inner Ethernet frame. If
inner VLAN is included in the VXLAN frame or a VLAN is supposed to be
added based on configuration, the VXLAN gateway decapsulates the
VXLAN packet and remarks the QoS field of the outgoing Ethernet frame
based on VXLAN Outer Ethernet Header QoS bits. The switch SHOULD
copy the Q-Flags of VXLAN Outer Ethernet Header into IEEE 802.1p
Priory Code Point (PCP) field in VLAN tag.
6. Quality of Service Operation at VXLAN Encapsulation Point
There are two types of VXLAN packet senders, that is, a VXLAN enabled
NVE or a VXLAN gateway.
For a VXLAN enabled NVE, the upstream procedure is:
Reception of Frames
The VXLAN enabled NVE receives an Ethernet packet from a hosting
VM.
Lookup
Making use of the destination of the Ethernet packet, the VXLAN
enabled NVE looks up MAC-NVE mapping table, and retrieves IP
address of destination NVE.
Acquisition of QoS parameters
There are two different ways to acquire QoS parameters for VXLAN
encapsulation. The first is a dynamic one which requires a VXLAN
enabled NVE has Deep Packet Inspection (DPI) capability and can
identify different application types. The second is a static one
Xia, et al. Expires September 6, 2015 [Page 7]
Internet-Draft Quality of Service Marking March 2015
which requires a VM manager to assign QoS parameters to different
VNIs based on premium that different tenancies pay.
Encapsulation of frames
The NVE then encapsulates the packet using VXLAN format with
acquired QoS parameters and VNI. The specific format is given in
Section 4. After the frame is encapsulated it is sent out
upstream to the network.
For a VXLAN gateway, packets are encapsulated using VXLAN format with
QoS field in a similar way. Once the VXLAN gateway receives a packet
from a non-VXLAN domain, it encapsulates the packet with QoS
parameters which are acquired through DPI or priorities of tenancies.
7. QoS processing for VXLAN outer IP header
QoS is user experience of end-to-end network operation. A packet
from VM A to VM B normally traverses such network entities
sequentially as virtual switch A which is co-located with VM A, TOR
switch A, aggregation switch A, a core switch, aggregation switch B,
TOR switch B, virtual switch B. VXLAN processing only takes place in
virtual switches, and all other network entities only execute IP
forwarding. VXLAN QoS mapping to outer IP header at virtual switch A
is needed to achieve end-to-end QoS.
Six bits of the Differentiated Services Field (DS field) are used as
a codepoint (DSCP) to select the per hop behaviour (PHB) a packet
experiences at each node in a Differentiated Services Domain
[RFC2474]. DS field is 8 bits long, 6 bits of it are used as DSCP
and two bits are unused. DS field is carried in both IPv4 and IPv6
packet headers.
Using 6 bits of DS field, it is possible to define 64 codepoints. A
pool of 32 RECOMMENDED codepoints called Pool 1 is standardized by
IANA. 8 of these 32 codepoints are called class selector (CS)
codepoints, from CS0 corresponding to '000000' to CS7 corresponding
to '111000' codepoints. There are also 12 assured forwarding (AF)
codepoints [RFC2597], an expedited forwarding (EF) per hop behavior
[RFC3246] and VOICE-ADMIT codepoint for capacity-admitted traffic
[RFC5865]. In this document we use class selector codepoints. Other
codepoints are out of scope.
When a packet forwarded from non-VXLAN domain to VXLAN domain through
a VXLAN gateway, DSCP field of outer IP header for unicast packets
should be marked based on VXLAN QoS using the class selector
codepoints, i.e. 'xxx000' that corresponds to VXLAN QoS marking, i.e.
Xia, et al. Expires September 6, 2015 [Page 8]
Internet-Draft Quality of Service Marking March 2015
with xxx assigned based on static or dynamic QoS markings defined
above in Section 4.
8. Security Considerations
Special security considerations in [RFC7348] are applicable.
9. IANA considerations
None.
10. Acknowledgements
The authors are grateful to Brian Carpenter, David Black, Erik
Nordmark for their constructive comments on our work.
11. References
11.1. Normative References
[RFC0826] Plummer, D., "Ethernet Address Resolution Protocol: Or
converting network protocol addresses to 48.bit Ethernet
address for transmission on Ethernet hardware", STD 37,
RFC 826, November 1982.
[RFC0791] Postel, J., "Internet Protocol", STD 5, RFC 791, September
1981.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2474] Nichols, K., Blake, S., Baker, F., and D. Black,
"Definition of the Differentiated Services Field (DS
Field) in the IPv4 and IPv6 Headers", RFC 2474, December
1998.
[RFC2475] Blake, S., Black, D., Carlson, M., Davies, E., Wang, Z.,
and W. Weiss, "An Architecture for Differentiated
Services", RFC 2475, December 1998.
[RFC2597] Heinanen, J., Baker, F., Weiss, W., and J. Wroclawski,
"Assured Forwarding PHB Group", RFC 2597, June 1999.
[RFC3246] Davie, B., Charny, A., Bennet, J., Benson, K., Le Boudec,
J., Courtney, W., Davari, S., Firoiu, V., and D.
Stiliadis, "An Expedited Forwarding PHB (Per-Hop
Behavior)", RFC 3246, March 2002.
Xia, et al. Expires September 6, 2015 [Page 9]
Internet-Draft Quality of Service Marking March 2015
[RFC4594] Babiarz, J., Chan, K., and F. Baker, "Configuration
Guidelines for DiffServ Service Classes", RFC 4594, August
2006.
[RFC5865] Baker, F., Polk, J., and M. Dolly, "A Differentiated
Services Code Point (DSCP) for Capacity-Admitted Traffic",
RFC 5865, May 2010.
[I-D.ietf-nvo3-arch]
Black, D., Hudson, J., Kreeger, L., Lasserre, M., and T.
Narten, "An Architecture for Overlay Networks (NVO3)",
draft-ietf-nvo3-arch-02 (work in progress), October 2014.
[IEEE802.1D]
IEEE, "Virtual Bridged Local Area Networks", IEEE Std
802.1D-2005, May 2006.
11.2. Informative References
[RFC7348] Mahalingam, M., Dutt, D., Duda, K., Agarwal, P., Kreeger,
L., Sridhar, T., Bursell, M., and C. Wright, "Virtual
eXtensible Local Area Network (VXLAN): A Framework for
Overlaying Virtualized Layer 2 Networks over Layer 3
Networks", RFC 7348, August 2014.
[I-D.geib-tsvwg-diffserv-intercon]
Geib, R. and D. Black, "DiffServ interconnection classes
and practice", draft-geib-tsvwg-diffserv-intercon-08 (work
in progress), November 2014.
[I-D.sarikaya-nvo3-proxy-vxlan]
Sarikaya, B. and F. Xia, "Virtual eXtensible Local Area
Network over IEEE 802.1Qbg", draft-sarikaya-nvo3-proxy-
vxlan-00 (work in progress), October 2014.
Authors' Addresses
Frank Xia
Huawei Technologies Co., Ltd.
101 Software Avenue, Yuhua District
Nanjing, Jiangsu 210012, China
Phone: ++86-25-56625443
Email: xiayangsong@huawei.com
Xia, et al. Expires September 6, 2015 [Page 10]
Internet-Draft Quality of Service Marking March 2015
Behcet Sarikaya
Huawei Technologies Co., Ltd.
5340 Legacy Dr. Building 3
Plano, TX 75024
Phone: +1 972-509-5599
Email: sarikaya@ieee.org
Shi Fan
China Telecom
Room 708, No.118, Xizhimennei Street
Beijing , P.R. China 100035
Phone: +86-10-58552140
Email: shifan@ctbri.com.cn
Xia, et al. Expires September 6, 2015 [Page 11]
