Internet DRAFT - draft-cuspdt-rtgwg-cu-separation-infor-model
draft-cuspdt-rtgwg-cu-separation-infor-model
rtgwg S. Hu
Internet-Draft China Mobile
Intended status: Informational Donald. Eastlake
Expires: April 25, 2019 M. Wang, Ed.
Huawei
V. Lopez
Telefonica
F. Qin
Z. Li
China Mobile
T. Chua
Singapore Telecommunications Limited
October 22, 2018
Information Model of Control-Plane and User-Plane Separation BNG
draft-cuspdt-rtgwg-cu-separation-infor-model-03
Abstract
To improve network resource utilization and reduce operational
expense, the Control-Plane and User-Plane separation concept is
defined in Broadband Forum TR-384. This document describes the
information model for the interface between the Control-Plane (CP)
and the User-Plane (UP) in the CP/UP separation BNG. This
information model may involve both the control channel interface and
the configuration channel interface. The interface for the control
channel allows the Control-Plane to send flow tables to the User-
Plane, such as user's information table, user's interface table, and
user's QoS table. And it also allows the User-Plane to report
resource and statistics information to the Control-Plane. The
interface for the configuration channel is in charge of the protocol
version negotiation between the Control-Plane and User-Plane, the
configuration for devices of the Control-Plane and User-Plane, and
the reports of User-Plane's capabilities, etc. The information model
defined in this document supports defining a standardized data model.
Such a data model can be used to specify an interface to the CU
separation BNG.
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 https://datatracker.ietf.org/drafts/current/.
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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 April 25, 2019.
Copyright Notice
Copyright (c) 2018 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
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described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Concept and Terminology . . . . . . . . . . . . . . . . . . . 3
2.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3
3. Control Plane and User Plane Separation BNG Information Model
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3.1. Service Data Model Usage . . . . . . . . . . . . . . . . 6
4. Information Model . . . . . . . . . . . . . . . . . . . . . . 8
4.1. Information Model for Control-Plane . . . . . . . . . . . 9
4.1.1. User-Related Information . . . . . . . . . . . . . . 11
4.1.1.1. User Basic Information Model . . . . . . . . . . 11
4.1.1.2. IPv4 Information Model . . . . . . . . . . . . . 12
4.1.1.3. IPv6 Information Model . . . . . . . . . . . . . 13
4.1.1.4. QoS Information Model . . . . . . . . . . . . . . 14
4.1.2. Interface Related Information . . . . . . . . . . . . 15
4.1.2.1. Interface Information Model . . . . . . . . . . . 15
4.1.3. Device Related Information . . . . . . . . . . . . . 16
4.1.3.1. Address field distribute Table . . . . . . . . . 17
4.2. Information Model for User Plane . . . . . . . . . . . . 17
4.2.1. Port Resources of UP . . . . . . . . . . . . . . . . 18
4.2.2. Traffic Statistics Infor . . . . . . . . . . . . . . 19
5. Security Considerations . . . . . . . . . . . . . . . . . . . 20
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 20
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 20
7.1. Normative References . . . . . . . . . . . . . . . . . . 20
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7.2. Informative References . . . . . . . . . . . . . . . . . 21
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 21
1. Introduction
To improve network resource utilization and reduce operational
expense, the Control-Plane and User-Plane separation concept is
defined in Broadband Forum [TR-384]. The motivation for and
architecture of the Control-Plane and User-Plane separation BNG is
discussed in [I.D.cuspdt-rtgwg-cu-separation-bng-architecture].
This document describes an information model for the interface
between the Control-Plane (CP) and the User-Plane (UP) separation in
the CP / UP Separated BNG. This information model may involve both
the control channel interface and the configuration channel
interface. The interface for control channel allows the Control-
Plane to send several flow tables to the User-Plane, such as user's
information table, user's interface table, and user's QoS table, etc.
And it also allows the User-Plane to report the resources and
statistics information to the Control-Plane. The interface for
configuration channel is in charge of the protocol version
negotiation of protocols between the Control-Plane and User-Plane,
the configuration for the devices of Control-Plane and User-Plane,
and the report of User-Plane's capabilities, etc. The information
model defined in this document enables supports defining a
standardized data model. Such a data model can be used to define an
interface to the CU separation BNG.
2. Concept and 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].
2.1. Terminology
BNG: Broadband Network Gateway. A broadband remote access server
(BRAS, B-RAS or BBRAS) routes traffic to and from broadband remote
access devices such as digital subscriber line access multiplexers
(DSLAM) on an Internet service provider's (ISP) network. BRAS can
also be referred to as a Broadband Network Gateway (BNG).
CP: Control Plane. CP is a user control management component which
supports the management of UP's resources such as the user entry and
forwarding policy
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UP: User Plane. UP is a network edge and user policy implementation
component. The traditional router's Control Plane and Forwarding
Plane are both preserved on BNG devices in the form of a user plane.
3. Control Plane and User Plane Separation BNG Information Model
Overview
Briefly, a CU separation BNG is made up of a centralized CP and a set
of UPs. The CP is a user control management component that manages
UP's resources such as the user entry and forwarding policy, for
example, the access bandwidth and priority management. The UP is a
network edge and user policy implementation component. It can
support the forwarding plane functions on traditional BNG devices,
such as traffic forwarding, QoS, and traffic statistics collection,
and it can also support the control plane functions on traditional
BNG devices, such as routing, multicast, etc.
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+-----+ +-----+ +-----+ +-----+
|EMS | |DHCP | |AAA | |policy
| | |server |server |server
+----|+ +---|-+ +--|--+ +--|--+
| | | |
| | | |
| | | |
| | | |
+----|---------|---------|---------|----+
| +--|----+ +--|--+ +---|--+ +----|--+ |
| |address| | sub | | AAA | |service| |
| |mgt | | Mgt | | | |control| |
| +-------+ +-----+ +------+ +-------+ |
| | Control Plane
| +--------------------------------+ |
| | User plane management | |
| | | |
| +-------------|------------------+ |
+-----------------|---------------------+
|
|
|
|----------------|-----------------|
| | |
| | |
+--------|-----+ +------|-------+ +------|------+
| +---------+ | | +---------+ | |+-----|----+ |
| | routing | | | | routing | | || routing | |
| | control | | | | control | | || control | |
| +---------+ | | +---------+ | |+----------+ |
| +----------+ | | +----------+ | |+----------+ | User Plane
| |forwarding| | | |forwarding| | ||forwarding| |
| |plane | | | |plane | | ||plane | |
| +----------+ | | +----------+ | |+----------+ |
+--------------+ +--------------+ +-------------+
Figure 1. CU Separated BNG
The CU separated BNG is shown in Figure 1. The BNG Control Plane
could be virtualized and centralized, which provides significant
benefits such as centralized session management, flexible address
allocation, high scalability for subscriber management capacity, and
cost-efficient redundancy, etc. The functional components inside the
BNG Service Control Plane can be implemented as Virtual Network
Functions (VNFs) and hosted in a Network Function Virtualization
Infrastructure (NFVI).
The User Plane Management module in the BNG control plane centrally
manages the distributed BNG User Planes (e.g. load balancing), as
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well as the setup, deletion, maintenance of channels between Control
Planes and User Planes. Other modules in the BNG control plane, such
as address management, AAA, and etc., are responsible for the
connection with outside subsystems in order to provide the service.
The routing control and forwarding Plane in the BNG User Plane
(local) could be distributed across the infrastructure.
3.1. Service Data Model Usage
The idea of this information model is to propose a set of generic and
abstract information models to be used in both Control Plane and User
Planes. A typical scenario would be that this model can be used as a
compendium to realize the communication between the Control Plane and
User Planes of the CU separation BNG.
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-----------------
//// \\\\
//// \\\\
// Cloud \\
| |
| |
| |
| |
| +-----------------+ |
| | Control Plane | |
\\ | | //
\\\\ +---------+-------+ ////
\\\\ | ////
------------------
|
+------------------+-----------+-----+
| | | |
User's information IP address QoS: .......
May Including: ...... CIR; |
User ID; | PIR; |
User MAC; | CBS; |
Access method(PPPoE, | PBS; |
IPoE, etc) ...... | ...... |
| | | |
+------------------V-----------+-----+
|
+----+
| -------
| /// \\\
+------+ +-------v---------+ +--------+ | |
| OTL | | User Plane | | Core | | Internet |
| +-------+ +-------+ Routing|-----| |
+------+ +-----------------+ +--------+ \\\ ///
-------
Figure 2. CU Separation BNG
As shown in Figure 2, when users access the BNG network, the control
plane solicits these users' information (such as user's ID, user's
MAC, user's access methods, for example via PPPoE/IPoE), associates
them with available bandwidth which is reported by User planes, and
based on the service's requirements generates a set of tables, which
may include user's information, user's IP address, and QoS. Then the
control plane can transmit these tables to the User planes. User
planes receive these tables, parse them, matches these rules, and
then performs corresponding actions.
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4. Information Model
This section specifies the information model in Routing Backus-Naur
Form [RFC5511]. This grammar intends to help readers better
understand the English text description in order to derive a data
model. However it may not provide all the details provided by the
English text. When there is a lack of clarity, the English text will
take precedence.
This section describes the information model that represents the
interface of the CU separation BNG that is language and protocol
neutral.
The following Routing BNF grammar describes the Overview of
Information Model for CU separation BNG.
<cu-separation-bng-infor-model>::=<control-plane-information-model>
<user-plane-information-model>
<control-plane-information-model>::=<user-related-infor-model>
<interface-related-infor-model>
<device-related-infor-model>
<user-related-infor-model>::= <user-basic-information>
[<ipv4-informatiom>]|[<ipv6-information>]
[<qos-information>]
<user-basic-information> :: = <USER_ID> <MAC_ADDRESS>
[<ACCESS_TYPE>][<SESSION_ID>]
[<INNER_VLAN-ID>][<OUTER_VLAN_ID>]
<USER_INTERFACE>
<ipv4-informatiom>::=<USER_ID><USER_IPV4>
<MASK_LENGTH><GATEWAY>
<VRF>
<ipv6-information>::=<USER_ID>(<USER_IPV6>
<PREFIX_LEN>)|(<PD_ADDRESS><PD_PREFIX_LEN>)
<VRF>
<qos-information>::=<USER_ID>
(<CIR><PIR><CBS><PBS>)
[<QOS_PROFILE>]
<interface-related-infor-model>::=<interface-information>
<interface-information>::=<IFINDEX><BAS_ENABLE>
<service-type>
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<service-type>::=<PPP_Only><IPV4_TRIG>
<IPV6_TRIG><ND-TRIG>
<ARP_PROXY>
<device-related-infor-model>::=<address-field-distribute>
<address-field-distribute>::=<ADDRESS_SEGMENT><ADDRESS_SEGMENT_MASK>
<ADDRESS_SEGMENT_VRF><NEXT_HOP>
<IF_INDEX><MASK_LENGTH>
<user-plane-information-model>::=<port-resources-infor-model>
<traffic-statistics>
<port-resource-information>::=<IF_INDEX><IF_NAME>
<IF_TYPE><LINK_TYPE>
<MAC_ADDRESS><IF_PHY_STATE>
<MTU>
<traffic-statistics-information>::=<USER_ID><STATISTICS_TYPE>
<INGRESS_STATIISTICS_PACKETS>
<INGRESS STATISTICS_BYTES>
<EGRESS_STATISTICS_PACKETS>
<EGRESS_STATISTICS_BYTES>
4.1. Information Model for Control-Plane
This section describes information model for the Control-Plane (CP).
As mentioned in Section 3, the Control Plane is a user control
management component which manages the user's information, User-
Plane's resources and forwarding policy, etc. The control plane can
generate several tables which contain a set of rules based on the
resources and specific requirements of user's service. After that,
the control plane sends the tables to User Planes, and User planes
receive the tables, parse them, match the rules, and then perform
corresponding actions.
The Routing Backus-Naur Form grammar below specifies the Information
model for Control-Plane:
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<control-plane-information-model>::=<user-related-infor-model>
<interface-related-infor-model>
<device-related-infor-model>
<user-related-infor-model>::= <user-basic-information>
[<ipv4-informatiom>]|[<ipv6-information>]
[<qos-information>]
<user-basic-information> :: = <USER_ID> <MAC_ADDRESS>
[<ACCESS_TYPE>][<SESSION_ID>]
[<INNER_VLAN-ID>][<OUTER_VLAN_ID>]
<USER_INTERFACE>
<ipv4-informatiom>::=<USER_ID><USER_IPV4>
<MASK_LENGTH><GATEWAY>
<VRF>
<ipv6-information>::=<USER_ID>(<USER_IPV6>
<PREFIX_LEN>)|(<PD_ADDRESS><PD_PREFIX_LEN>)
<VRF>
<qos-information>::=<USER_ID>
(<CIR><PIR><CBS><PBS>)
[<QOS_PROFILE>]
<interface-related-infor-model>::=<interface-information>
<interface-information>::=<IFINDEX><BAS_ENABLE>
<service-type>
<service-type>::=<PPP_Only><IPV4_TRIG>
<IPV6_TRIG><ND-TRIG>
<ARP_PROXY>
<device-related-infor-model>::=<address-field-distribute>
<address-field-distribute>::=<ADDRESS_SEGMENT><ADDRESS_SEGMENT_MASK>
<ADDRESS_SEGMENT_VRF><NEXT_HOP>
<IF_INDEX><MASK_LENGTH>
user-related-infor-model: presents the attributes that can describe
the user's profile, such as user's basic information, qos, and IP
address.
interface-related-infor-model: presents the attributes that relate to
some physical/virtual interface. This model can be used to indicate
which kinds of service can be supported by interfaces.
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device-related-infor-model: presents the attributes which relate to a
specific device. For example the control plane can manage and
distribute the users, which belong to same subnet, to some specific
devices. And the user plane's devices provide corresponding service
for these users.
4.1.1. User-Related Information
The user related information is a collection of attributes bound to
specific users. For example, the control plane can use a unified ID
to distinguish different users and distribute the IP address and QoS
rules to a specific user. In this section, the user related
information models are presented. The user related information
models include the user information model, IPv4/IPv6 information
model, QoS information model, etc.
The Routing Backus-Naur Form grammar below specifies the user related
information model:
<user-related-infor-model>::= <user-basic-information>
[<ipv4-informatiom>]|[<ipv6-information>]
[<qos-information>]
<user-basic-information> :: = <USER_ID> <MAC_ADDRESS>
[<ACCESS_TYPE>][<SESSION_ID>]
[<INNER_VLAN-ID>][<OUTER_VLAN_ID>]
<USER_INTERFACE>
<ipv4-informatiom>::=<USER_ID><USER_IPV4>
<MASK_LENGTH><GATEWAY>
<VRF>
<ipv6-information>::=<USER_ID>(<USER_IPV6>
<PREFIX_LEN>)|(<PD_ADDRESS><PD_PREFIX_LEN>)
<VRF>
<qos-information>::=<USER_ID>
(<CIR><PIR><CBS><PBS>)
[<QOS_PROFILE>]
4.1.1.1. User Basic Information Model
The User Basic Information model contains a set of attributes to
describe the basic information of a specific user, such as the user's
MAC address, access type (via PPPoE, IPoE, etc), inner VLAN ID, outer
VLAN ID, etc.
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The Routing Backus-Naur Form grammar below specifies the user basic
information model:
<user-basic-information> :: = <USER_ID> <MAC_ADDRESS>
[<ACCESS_TYPE>][<SESSION_ID>]
[<INNER_VLAN-ID>][<OUTER_VLAN_ID>]
<USER_INTERFACE>
USER_ID (4 bytes): is the identifier for a user. This parameter is
unique and mandatory. It can be used to distinguish different users.
MAC_ADDRESS (6 bytes): is the MAC address of the user.
ACCESS_TYPE (2 bytes): This attribute is an optional parameter. It
can be used to indicate the protocol being used for the user's
access, such as PPPoE, IPoE, etc.
SESSION_ID (4 bytes): This attribute is an optional parameter. It
can be used as the identifier of PPPoE session.
INNER_VLAN-ID (2 bytes): The 12-bit identifier of user's inner VLAN
in network byte order. The unused high-order 4 bits MUST be sent as
zero and ignored on receipt.
OUTER_VLAN_ID (2 bytes): The 12-bit identifier of user's outer VLAN
in network byte order. The unused high-order 4 bits MUST be sent as
zero and ignored on receipt.
USER_INTERFACE (4 bytes): This attribute specifies the binding
interface of a specific user. The IfIndex of the interface MAY be
included. This is the 32-bit IfIndex assigned to the interface by
the device as specified by the Interfaces Group MIB [RFC2863]. The
IfIndex can be utilized within a management domain to map to an
actual interface, but it is also valuable in public applications
[RFC5837]. The IfIndex can be used as an opaque token to discern
which interface of the User-Plane is providing corresponding service
for specific user.
4.1.1.2. IPv4 Information Model
The IPv4 information model presents the user's IPv4 parameters. It
is an optional constructs. The Routing Backus-Naur Form grammar
below sepcifies the user's IPv4 information model:
<ipv4-informatiom>::=<USER_ID><USER_IPV4>
<MASK_LENGTH><GATEWAY>
<VRF>
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USER_ID (4 bytes): is the identifier of user. This parameter is
unique and mandatory. This attribute is used to distinguish
different users. In conjunction with other IPv4 parameters it links
the user to the user's IPv4 information.
USER_IPV4 (4 bytes): This attribute specifies the user's IPv4
address, It is usually used in user plane discovery and ARP reply
message.
MASK_LENGTH (4 bytes): This attribute specifies the user's subnet
mask length which can identify a range of IP addresses that are on
the same network.
GATEWAY (4 bytes): This attribute specifies the user's gateway, and
is usually used in User Plane discovery and ARP reply message.
VRF (4 bytes): is the identifier of VRF instance.
4.1.1.3. IPv6 Information Model
The IPv6 information model presents the user's IPv6 parameters. It
is an optional constructs. The Routing Backus-Naur Form grammar
below specifies the user's IPv6 information model:
<ipv6-information>::=<USER_ID>(<USER_IPV6>
<PREFIX_LEN>)|(<PD_ADDRESS><PD_PREFIX_LEN>)
<VRF>
USER_ID (4 bytes): is the identifier of user. This parameter is
unique and mandatory. This attribute is used to distinguish
different users. in conjunction with other IPv6 parameters, I tlink
the user to the user's IPv6 information.
USER_IPV6 (2 bytes): This attribute specifies the user's IPv6
address. It is usually used in neighbor discovery (ND discovery).
PREFIX_LEN (4 bytes): This attribute specifies the user's subnet
prefix lengths which can identify a range of IP addresses that are on
the same network.
PD_ADDRESS (4 bytes): In IPv6 networking, DHCPv6 prefix delegation is
used to assign a network address prefix and automate configuration
and provisioning of the public routable addresses for the network.
This attribute specifies the user's DHCPv6 prefix delegation address,
and is usually used in neighbor discovery (ND discovery).
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PD_PREFIX_LEN (4 bytes): This attribute specifies the user's DHCPv6
delegation prefix length, and it's usually used in neighbor discovery
(ND discovery).
VRF (4 bytes): is the identifier of a VRF instance
4.1.1.4. QoS Information Model
In the CU separation BNG, the Control-Plane (CP) generates the QoS
table base based on the UP's bandwidth resources and the specific QoS
requirements ofof the user's services. This table contains a set of
QoS matching rules such as user's committed information rate, peak
information rate, committed burst size, etc. And itIs is an optional
constructs. The Routing Backus-Naur Form grammar below
illustratesspecifies the user's qos information model:
<qos-information>::=<USER_ID>
(<CIR><PIR><CBS><PBS>)
[<QOS_PROFILE>]
USER_ID (4 bytes): is the identifier of user. This parameter is
unique and mandatory. This attribute is used to distinguish
different users. within conjunction with other qos parameters it
links the user to the user's qos information.
CIR (4 bytes): In a BNG network, the Committed Information Rate (CIR)
is the bandwidth available for a user guaranteed by an internet
service provider under normal conditions. This attribute is used to
indicate the user's committed information rate, and it usually
appears with other qos attributes (such as PIR, CBS, PBS, etc) to
give the user's QoS profile.
PIR (4 bytes): Peak Information Rate (PIR) is a burstable rate set on
routers and/or switches that allow throughput bursts. This attribute
is used to indicate the user's peak information rate. In conjunction
with with other QoS attributes (such as CIR, CBS, PBS, etc) it is
used to give the user's QoS profile.
CBS (4 bytes): The Committed Burst Size (CBS) specifies the relative
amount of reserved buffers for a specific ingress network's
forwarding class queue or egress network's forwarding class queue.
This attribute is used to indicate the user's committed burst size.
In conjunction with other qos attributes (such as CIR, PIR, PBS, etc)
it is used to give the user's QoS profile.
PBS (4 bytes): The Peak Burst Size (PBS) specifies the maximum size
of the first token bucket. This attribute is used to indicate the
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user's peak burst size. In conjunction with other qos attributes
(such as CIR, PIR, CBS, etc) it is used to give the user's QoS
profile.
QOS_PROFILE (4 bytes): This attribute specifies the standard profile
provided by the operator. It can be used as a QoS template that is
defined as a list of classes of services and associated properties.
The properties may include:
o Rate-limit: used to rate-limit the class of service. The value
is expressed as a percentage of the global service bandwidth.
o latency: used to define the latency constraint of the class.
The latency constraint can be expressed as the lowest possible
latency or a latency boundary expressed in milliseconds.
o jitter: used to define the jitter constraint of the class. The
jitter constraint can be expressed as the lowest possible jitter
or a jitter boundary expressed in microseconds.
o bandwidth: used to define a guaranteed amount of bandwidth for
the class of service. It is expressed as a percentage.
4.1.2. Interface Related Information
This model contains the necessary information for an interface. It
is used to indicate which kind of service can be supported by this
interface. The Routing Backus-Naur Form grammar below specifies the
interface related information model:
<interface-related-infor-model>::=<interface-information>
<interface-information>::=<IFINDEX><BAS_ENABLE>
<service-type>
<service-type>::=<PPP_Only><IPV4_TRIG>
<IPV6_TRIG><ND-TRIG>
<ARP_PROXY>
4.1.2.1. Interface Information Model
The interface model mentioned here is a logical construct that
identifies a specific process or a type of network service. In CU
separation BNG network, the Control-Plane (CP) generates the
Interface-Infor table based on the available resources, which are
received from the User-Plane (UP), and the specific requirements of
user's services.
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The Routing Backus-Naur Form grammar below specifies the interface
information model:
<interface-information>::=<IFINDEX><BAS_ENABLE>
<service-type>
<service-type>::=<PPP_Only><IPV4_TRIG>
<IPV6_TRIG><ND-TRIG>
<ARP_PROXY>
IFINDEX (4 bytes): The IfIndex is the 32-bit index assigned to the
interface by the device as specified by the Interfaces Group MIB
[RFC2863]. The IfIndex can be utilized within a management domain to
map to an actual interface, but it is also valuable in public
applications. The IfIndex can be used as an opaque token to discern
which interface of the User-Plane is providing the corresponding
service for specific user.
BAS_ENABLE (2 bytes): This is a flag, and if it is TRUE, the BRAS is
enabled on this interface.
PPP_Only (2 bytes): This is a flag, and if it is TRUE, the interface
only supports PPP user.
IPV4_TRIG (2 bytes): This is a flag, and if it is TRUE, the interface
supports the user being triggered to connect to the internet by using
an IPv4 message.
IPV6_TRIG (2 bytes): This is a flag, and if it is TRUE, the interface
supports that the user being triggered to connect to the internet by
using an IPv6 message.
ND-TRIG (2 bytes): This is a flag, and if it is TRUE, the interface
supports the user being triggered to connect to the internet by using
a neighbor discovery message.
ARP_PROXY (2 bytes): This is a flag, and if it is TRUE, ARP PROXY is
enabled on this interface.
4.1.3. Device Related Information
The device related information model presents the attributes which
relate to a specific device. For example the control plane can
manage and distribute the users, who belong to the same subnet, to
some specific devices. And then the user plane's devices can provide
the corresponding service for these users. The Routing Backus-Naur
Form grammar below specifies the device related information model:
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<device-related-infor-model>::=<address-field-distribute>
<address-field-distribute>::=<ADDRESS_SEGMENT><ADDRESS_SEGMENT_MASK>
<ADDRESS_SEGMENT_VRF><NEXT_HOP>
<IF_INDEX><MASK_LENGTH>
4.1.3.1. Address field distribute Table
In the CU separation BNG information model, the Control-Plane (CP)
generates and sends this Address field distribute table to UP. Based
on this table, the user-plane's devices can be divided into several
blocks, and each block is in charge of working for users with the
same subnet. The Routing Backus-Naur Form grammar below illustrates
the address field sepcifies information model:
<address-field-distribute>::=<ADDRESS_SEGMENT><ADDRESS_SEGMENT_MASK>
<ADDRESS_SEGMENT_VRF><NEXT_HOP>
<IF_INDEX><MASK_LENGTH>
4.2. Information Model for User Plane
This section describes the information model for the interface of to
the User Plane (UP). As mentioned in section Section 3, the UP is a
network edge and user policy implementation component. It supports
the following: Forwarding plane functions on traditional BNG devices,
including traffic forwarding, QoS, and traffic statistics collection
and Control plane functions on traditional BNG devices, including
routing, multicast, and MPLS.
In CU separation BNG information model, the CP generates tables and
provides the entries. The UP plays two roles:
1. It receives these tables, parses them, then performs
corresponding actions.
2. It also generates several tables to report the available
resources (such as usable interfaces, etc.) and statistical
information to CP.
The Routing Backus-Naur Form grammar below specifies the User Plane
information model:
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<user-plane-information-model>::=<port-resources-infor-model>
<traffic-statistics>
port-resource-information>::=<IF_INDEX><IF_NAME>
<IF_TYPE><LINK_TYPE>
<MAC_ADDRESS><IF_PHY_STATE>
<MTU>
<traffic-statistics-information>::=<USER_ID><STATISTICS_TYPE>
<INGRESS_STATIISTICS_PACKETS>
<INGRESS STATISTICS_BYTES>
<EGRESS_STATISTICS_PACKETS>
<EGRESS_STATISTICS_BYTES>
4.2.1. Port Resources of UP
The User Plane can generate the network resource table, which
contains a bunch of attributes to present the available network
resources, for example the usable interfaces.
The Figure Routing BNF grammar below illustratesspecifies the Port
Resources Information Table of User-Plane:
<port-resource-information>::<IF_INDEX><IF_NAME>
<IF_TYPE><LINK_TYPE>
<MAC_ADDRESS><IF_PHY_STATE>
<MTU>
IFINDEX (4 bytes): IfIndex is the 32-bit index assigned to the
interface by the device as specified by the Interfaces Group MIB
[RFC2863]. The IfIndex can be utilized within a management domain to
map to an actual interface, but it is also valuable in public
applications. The IfIndex can be used as an opaque token to discern
which interface of the User-Plane is available.
IF_NAME (64 bytes): the textual name of the interface. The value of
this object should be the name of the interface as assigned by the
local device and should be suitable for use in commands entered at
the device's "console". This might be a text name, such as "le0" or
a simple port number, such as "1", depending on the interface naming
syntax of the device. If several entries in the ifTable together
represent a single interface as named by the device, then each will
have the same value of ifName.
IF_TYPE (4 bytes): the type of interface, such as Ethernet, GE, Eth-
Trunk, etc.
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LINK_TYPE (4 bytes): This attribute specifies the type of link, such
as point-to-point, broadcast, multipoint, point-to-multipoint,
private and public (accessibility and ownership), etc.
MAC_ADDRESS (6 bytes): This attribute specifies the available
interface's MAC address.
IF_PHY_STATE (1 byte): The current operational state of the
interface. This is an enumeration type node:
1- Up: ready to pass packets;
2- Down
3- Testing: in some test mode;
4- Unknow: status cannot be determined for some reason;
5- Dormant;
6- Not present: some component is missing.
MTU: This attribute specifies the available interface's MTU (Maximum
Transmission Unit).
4.2.2. Traffic Statistics Infor
The user-plane also generates the traffic statistics table to report
the current traffic statistics.
The Figure below specifies the Traffic Statistics Infor model of
User-Plane:
<traffic-statistics-information>::=<USER_ID><STATISTICS_TYPE>
<INGRESS_STATIISTICS_PACKETS>
<INGRESS STATISTICS_BYTES>
<EGRESS_STATISTICS_PACKETS>
<EGRESS_STATISTICS_BYTES>
USER_ID (4 bytes): is the identifier of user. This parameter is
unique and mandatory. This attribute is used to distinguish
different users. In conjunction with other statistics parameters
such as ingress packets, egress packets, etc, it is used to report
the user's status profile.
STATISTICS_TYPE (4 bytes): This attributes specifies the traffic type
such as IPv4, IPv6, etc.
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INGRESS_STATIISTICS_PACKETS (8 bytes): This attribute specifies the
Ingress Statistics Packets of specific user.
INGRESS STATISTICS_BYTES (8 bytes): This attribute specifies the
Ingress Statistics Bytes of specific user.
EGRESS_STATISTICS_PACKETS (8 bytes): This attribute specifies the
Egress Statistics Packets of specific user.
EGRESS_STATISTICS_BYTES (8 bytes): This attribute specifies the
Egress Statistics Bytes of specific user.
5. Security Considerations
None.
6. IANA Considerations
None.
7. References
7.1. Normative References
[I-D.cuspdt-rtgwg-cu-separation-bng-architecture]
Hu, S., Qin, F., Li, Z., Chua, T., Wang, Z., and J. Song,
"Architecture for Control Plane and User Plane Separated
BNG", draft-cuspdt-rtgwg-cu-separation-bng-architecture-01
(work in progress), July 2018.
[I-D.cuspdt-rtgwg-cu-separation-bng-deployment]
Gu, R., Hu, S., and Z. Wang, "Deployment Model of Control
Plane and User Plane Separation BNG", draft-cuspdt-rtgwg-
cu-separation-bng-deployment-00 (work in progress),
October 2017.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC2863] McCloghrie, K. and F. Kastenholz, "The Interfaces Group
MIB", RFC 2863, DOI 10.17487/RFC2863, June 2000,
<https://www.rfc-editor.org/info/rfc2863>.
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[RFC5511] Farrel, A., "Routing Backus-Naur Form (RBNF): A Syntax
Used to Form Encoding Rules in Various Routing Protocol
Specifications", RFC 5511, DOI 10.17487/RFC5511, April
2009, <https://www.rfc-editor.org/info/rfc5511>.
[RFC5837] Atlas, A., Ed., Bonica, R., Ed., Pignataro, C., Ed., Shen,
N., and JR. Rivers, "Extending ICMP for Interface and
Next-Hop Identification", RFC 5837, DOI 10.17487/RFC5837,
April 2010, <https://www.rfc-editor.org/info/rfc5837>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
7.2. Informative References
[TR-384] Broadband Forum, ""Cloud Central Office Reference
Architectural Framework",", BBF TR-384, January. 2018.
Authors' Addresses
Shujun Hu
China Mobile
32 Xuanwumen West Ave, Xicheng District
Beijing, Beijing 100053
China
Email: hushujun@chinamobile.com
Donald Eastlake, 3rd
Huawei
1424 Pro Shop Court
Davenport, FL 33896
USA
Email: d3e3e3@gmail.com
Michael Wang (editor)
Huawei
101 Software Avenue, Yuhua District
Nanjing, Jiangsu 210012
China
Email: wangzitao@huawei.com
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Victor Lopez
Telefonica
Sur 3 building, 3rd floor, Ronda de la Comunicacion s/n
Madrid 28050
Spain
Email: victor.lopezalvarez@telefonica.com
Fengwei Qin
China Mobile
32 Xuanwumen West Ave, Xicheng District
Beijing, Beijing 100053
China
Email: qinfengwei@chinamobile.com
Zhenqiang Li
China Mobile
32 Xuanwumen West Ave, Xicheng District
Beijing, Beijing 100053
China
Email: lizhenqiang@chinamobile.com
Tee Mong Chua
Singapore Telecommunications Limited
31 Exeter Road, #05-04 Comcentre Podium Block
Singapore City 239732
Singapore
Email: teemong@singtel.com
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