Internet DRAFT - draft-zhang-mboned-multicast-info-model
draft-zhang-mboned-multicast-info-model
MBONED WG Zheng. Zhang
Internet-Draft Cui. Wang
Intended status: Standards Track ZTE Corporation
Expires: February 22, 2018 Ying. Cheng
China Unicom
August 21, 2017
Multicast Model
draft-zhang-mboned-multicast-info-model-02
Abstract
This document intents to provide a general and all-round multicast
model, which tries to stand at a high level to take full advantages
of existed multicast protocol models to control the multicast
network, and guides the deployment of multicast service. And also,
there will define several possible RPCs about how to interact between
multicast info model and multicast protocol models. This multicast
information model is mainly used by the management tools run by the
network operators in order to manage, monitor and debug the network
resources used to deliver multicast service, as well as gathering
some data from the 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 February 22, 2018.
Copyright Notice
Copyright (c) 2017 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
Provisions Relating to IETF Documents
Zhang, et al. Expires February 22, 2018 [Page 1]
Internet-Draft Multicast Model August 2017
(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. Design of the multicast model . . . . . . . . . . . . . . . . 3
3. UML Class Diagram for Multicast Info Model . . . . . . . . . 4
4. Model Structure . . . . . . . . . . . . . . . . . . . . . . . 5
5. Multicast Information Model . . . . . . . . . . . . . . . . . 7
6. Notifications . . . . . . . . . . . . . . . . . . . . . . . . 17
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 17
8. Normative References . . . . . . . . . . . . . . . . . . . . 17
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 18
1. Introduction
Currently, there are many multicast YANG models, such as PIM, MLD,
and BIER and so on. But all these models are distributed in
different working groups as separate files and focus on the protocol
itself. Furthermore, they cannot describe a high-level multicast
service required by network operators.
This document intents to provide a general and all-round multicast
model, which tries to stand at a high level to take full advantages
of these aforementioned models to control the multicast network, and
guides the deployment of multicast service.
This multicast information model is mainly used by the management
tools run by the network operators in order to manage, monitor and
debug the network resources used to deliver multicast service, as
well as gathering some data from the network.
Zhang, et al. Expires February 22, 2018 [Page 2]
Internet-Draft Multicast Model August 2017
+------------------------+
| Multicast Info |
+------------------------+
| | |
| | |
| +---------+ +----------+
| | EMS/NMS | |Controller|
| +---------+ +----------+
| | |
| | |
+------------------------------------------------+
| Network Element1.....N |
+------------------------------------------------+
Figure 1: Example usage of Multicast Model
Detailly,in figure 1, there is an example of usage of this multicast
model. Network operators can input this model to a controller who is
responsible to translate the information and invoke the corresponding
protocol models into configurations to configure the network elements
through NETCONF/RESTCONF/CLI. Or network operators can input this
model to the EMS/NMS to manage the network elements or configure the
network elements directly. On the other hand, when the network
elements detect failure or some other changes, the network operators
can collect these kind of notifications through this model to assist
locating the exact failure and responsing immediatly. for example,
when the network element suffers a failure of one MVPN neighbor, it
can notify to the EMS/NMS or Controller or to other Multicast Model
management tool directly to let the network operator take actions
immediately.
Specifically, in section 3, it provides a human readability of the
whole multicast network through UML class diagram, which frames
different multicast components and correlates them in a readable
fashion. Then, based on this UML class diagram, there is
instantiated and detailed YANG model in Section 5.
In other words, this document does not define any specific protocol
model, instead, it depends on many existed multicast protocol models
and relates several multicast information together to fulfill
multicast service.
2. Design of the multicast model
This model includes three layers: the multicast overlay, the
transport layer and the multicast underlay information.
Zhang, et al. Expires February 22, 2018 [Page 3]
Internet-Draft Multicast Model August 2017
Multicast overlay defines the features of multicast flow, such
as(vpnid, multicast source and multicast group) information, and
(ingress-node,egress-nodes) nodes information. If the transport
layer is BIER, there may define BIER information including
(Subdomain, ingress-node BFR-id, egress-nodes BFR-id). In data
center network, for fine-grained to gather the nodes belonging to the
same virtual network, there may need VNI-related information to
assist. If no (ingress-node, egress-nodes) information are defined
directly, there may need overlay multicast signaling technology, such
as MLD or MVPN, to collect these nodes information.
Multicast transport layer defines the type of transport technologies
that can be used to forward multicast flow, including BIER forwarding
type, MPLS forwarding type, or PIM forwarding type and so on. One or
several transport technologies could be defined at the same time. As
for the detailed parameters for each transport technology, this
multicast information model can invoke the corresponding protocol
model to define them.
Multicast underlay defines the type of underlay technologies, such as
OSPF, ISIS, BGP, PIM or BABEL and so on. One or several underlay
technologies could be defined at the same time. As for the specific
parameters for each underlay technology, this multicast information
model can depend the corresponding protocol model to configure them
as well.
3. UML Class Diagram for Multicast Info Model
The following is a UML diagram for Multicast Info Model.
Zhang, et al. Expires February 22, 2018 [Page 4]
Internet-Draft Multicast Model August 2017
+----------------+
| Multicast Info |
+----------------+
| | |Contain
+---------------------------+ | +---------------------------+
| | |
+-------------------+ +---------------------+ +--------------------+
| Multicast Overlay | | Multicast Transport | | Multicast Underlay |
+-------------------+ +---------------------+ +--------------------+
| | |Contain | | | | | invoke | | | | | invoke
+--------+ | +-------+ +----+ | | | +----+ +----+ | | | +----+
| | | | | | | | | | | | |
+--------------+ | +--------------+ +-----+ | | | +------+ +------+ | | | +------+
| Multi-Info | | | Ing/Eg Nodes | | PIM | | | | | MPLS | | OSPF | | | | | PIM |
+--------------+ | +--------------+ +-----+ | | | +------+ +------+ | | | +------+
|Group Address | | |Ingress Nodes | +----+ | +-----+ +----+ | +-----+
+--------------+ | +--------------+ | | | | | |
|Source Address| | |Egress Nodes | +----------+ | +--------+ +-----+ | +------+
+--------------+ | +--------------+ |Cisco Mode| | |BIER-TE | |BABEL| | | BGP |
|VPN Info | | | relate +----------+ | +--------+ +-----+ | +------+
+--------------+ | \|/ +----+ +----+
|VNI Info | | +----------------+ | |
+--------------+ | | BIER Nodes Info| +------+ +------+
| +----------------+ | BIER | | ISIS |
+--------+ | BFR-ID | +------+ +------+
| +----------------+
+--------------+
| Overlay Tech |
+--------------+
| MLD |
+--------------+
| MVPN |
+--------------+
| BGP |
+--------------+
| MLD-Snooping |
+--------------+
Figure 2: UML Class Diagram for Multicast Info Model
4. Model Structure
module: ietf-multicast-information
+--rw multicast-information
+--rw multicast-info* [vpn-id source-address source-wildcard group-address group-wildcard vni-type vni-value]
+--rw vpn-id uint32
+--rw source-address inet:ip-address
+--rw source-wildcard uint8
Zhang, et al. Expires February 22, 2018 [Page 5]
Internet-Draft Multicast Model August 2017
+--rw group-address inet:ip-address
+--rw group-wildcard uint8
+--rw vni-type virtual-type
+--rw vni-value uint32
+--rw multicast-overlay
| +--rw nodes-information
| | +--rw ingress-node? inet:ip-address
| | +--rw egress-nodes* [egress-node]
| | +--rw egress-node inet:ip-address
| +--rw bier-information
| | +--rw sub-domain? sub-domain-id
| | +--rw ingress-node? bfr-id
| | +--rw egress-nodes* [egress-node]
| | +--rw egress-node bfr-id
| +--rw overlay-technology
| +--rw (overlay-tech-type)?
| +--:(mld)
| +--:(mvpn)
| +--:(bgp)
| +--:(mld-snooping)
+--rw multicast-transport
| +--rw bier
| | +--rw sub-domain? sub-domain-id
| | +--rw (encap-type)?
| | | +--:(mpls)
| | | +--:(non-mpls)
| | | +--:(ipv6)
| | +--rw bitstringlength? uint16
| | +--rw set-identifier? si
| | +--rw ecmp? boolean
| | +--rw frr? boolean
| +--rw bier-te
| | +--rw sub-domain? sub-domain-id
| | +--rw (encap-type)?
| | | +--:(mpls)
| | | +--:(non-mpls)
| | +--rw bitstringlength? uint16
| | +--rw set-identifier? si
| | +--rw ecmp? boolean
| | +--rw frr? boolean
| +--rw cisco-mode
| | +--rw p-group? inet:ip-address
| | +--rw graceful-restart? boolean
| | +--rw bfd? boolean
| +--rw mpls
| | +--rw (mpls-tunnel-type)?
| | +--:(mldp)
| | | +--rw mldp-tunnel-id? uint32
Zhang, et al. Expires February 22, 2018 [Page 6]
Internet-Draft Multicast Model August 2017
| | | +--rw mldp-frr? boolean
| | | +--rw mldp-backup-tunnel? boolean
| | +--:(p2mp-te)
| | +--rw te-tunnel-id? uint32
| | +--rw te-frr? boolean
| | +--rw te-backup-tunnel? boolean
| +--rw pim
| +--rw graceful-restart? boolean
| +--rw bfd? boolean
+--rw multicast-underlay
+--rw underlay-requirement? boolean
+--rw bgp
+--rw ospf
| +--rw topology-id? uint16
+--rw isis
| +--rw topology-id? uint16
+--rw babel
+--rw pim
5. Multicast Information Model
<CODE BEGINS> file "ietf-multicast-information.yang"
module ietf-multicast-information {
namespace "urn:ietf:params:xml:ns:yang:ietf-multicast-information";
prefix multicast-info;
import ietf-inet-types {
prefix "inet";
}
organization " IETF MBONED( MBONE Deployment ) Working Group";
contact
"WG List: <mailto:bier@ietf.org>
WG Chair: Greg Shepherd
<mailto:gjshep@gmail.com>
WG Chair: Leonard Giuliano
<mailto:lenny@juniper.net>
Editor: Zheng Zhang
<mailto:zhang.zheng@zte.com.cn>
Editor: Cui Wang
<mailto:wang.cui1@zte.com.cn>
Editor: Ying Cheng
<mailto:chengying10@chinaunicom.cn>
";
Zhang, et al. Expires February 22, 2018 [Page 7]
Internet-Draft Multicast Model August 2017
description
"This module contains a collection of YANG definitions for
managing multicast information.";
revision 2017-08-20 {
description
"Add BGP and MLD-snooping overlay and BIER-TE transport.";
reference "https://tools.ietf.org/html/draft-zhang-mboned-multicast-info-model";
}
revision 2016-12-08 {
description
"Initial version.";
reference "https://tools.ietf.org/html/draft-zhang-mboned-multicast-info-model";
}
/*feature*/
grouping general-multicast {
description "The general multicast address information.";
leaf source-address {
type inet:ip-address;
description "The address of multicast source. The value set to zero
means that the receiver interests in all source that relevant to
one group.";
}
leaf source-wildcard {
type uint8;
description "The wildcard information of source.";
}
leaf group-address {
type inet:ip-address;
description "The address of multicast group.";
}
leaf group-wildcard {
type uint8;
description "The wildcard information of group.";
}
}
grouping m-addr {
description "The vpn multicast information.";
leaf vpn-id {
type uint32;
description "The vpn-id of the multicast flow.
If there is global instance, the vpnid value should be zero.";
}
uses general-multicast;
}
Zhang, et al. Expires February 22, 2018 [Page 8]
Internet-Draft Multicast Model August 2017
typedef virtual-type {
type enumeration {
enum "vxlan" {
description "The vxlan type.";
}
enum "virtual subnet" {
description "The nvgre type";
}
enum "vni" {
description "The geneve type";
}
}
description "The collection of virtual network type.";
}
grouping multicast-nvo3 {
description "The nvo3 multicast information.";
leaf vni-type {
type virtual-type;
description "The type of virtual network identifier. Include the Vxlan
NVGRE and Geneve.";
}
leaf vni-value {
type uint32;
description "The value of Vxlan network identifier, virtual subnet ID
or virtual net identifier.";
}
}
grouping multicast-feature {
description
"This group describe the different multicast information
in various deployments.";
uses m-addr;
uses multicast-nvo3;
}
grouping ip-node {
description "The IP information of multicast nodes.";
leaf ingress-node {
type inet:ip-address;
description "The ingress node of multicast flow. Or the ingress
node of MVPN and BIER. In MVPN, this is the address of ingress
PE; in BIER, this is the BFR-prefix of ingress nodes.";
}
list egress-nodes {
key "egress-node";
Zhang, et al. Expires February 22, 2018 [Page 9]
Internet-Draft Multicast Model August 2017
description "This ID information of one adjacency.";
leaf egress-node {
type inet:ip-address;
description
"The egress multicast nodes of multicast flow.
Or the egress node of MVPN and BIER. In MVPN, this is the
address of egress PE; in BIER, this is the BFR-prefix of
ingress nodes.";
}
}
}
/* should import from BIER yang */
typedef bfr-id {
type uint16;
description "The BFR id of nodes.";
}
typedef si {
type uint16;
description
"The type for set identifier";
}
typedef sub-domain-id {
type uint16;
description
"The type for sub-domain-id";
}
typedef bit-string {
type uint16;
description
"The bit mask of one bitstring.";
}
grouping bier-node {
description "The BIER information of multicast nodes.";
leaf sub-domain {
type sub-domain-id;
description "The sub-domain that this multicast flow belongs to.";
}
leaf ingress-node {
type bfr-id;
description "The ingress node of multicast flow. This is the
BFR-id of ingress nodes.";
}
list egress-nodes {
Zhang, et al. Expires February 22, 2018 [Page 10]
Internet-Draft Multicast Model August 2017
key "egress-node";
description "This ID information of one adjacency.";
leaf egress-node {
type bfr-id;
description
"The egress multicast nodes of multicast flow.
This is the BFR-id of egress nodes.";
}
}
}
grouping overlay-tech {
description "The possible overlay technologies for multicast service.";
choice overlay-tech-type {
case mld {
description "MLD technology is used for multicast overlay";
}
case mvpn {
description "MVPN technology is used for multicast overlay";
}
case bgp {
description "BGP technology is used for multicast overlay";
}
case mld-snooping {
description "MLD snooping technology is used for multicast overlay";
}
description "The collection of multicast overlay technology";
}
}
grouping multicast-overlay {
description "The node information that connect the ingress multicast
flow, and the nodes information that connect the egress multicast
flow.";
/*uses multicast-feature;*/
container nodes-information {
description "The ingress and egress nodes information.";
uses ip-node;
}
container bier-information {
description "The ingress and egress BIER nodes information.";
uses bier-node;
}
container overlay-technology {
description "The possible overlay technologies for multicast service.";
uses overlay-tech;
}
Zhang, et al. Expires February 22, 2018 [Page 11]
Internet-Draft Multicast Model August 2017
}
/*transport*/
grouping transport-bier {
description "The BIER transport information.";
leaf sub-domain {
type sub-domain-id;
description "The subdomain id that this multicast flow belongs to.";
}
choice encap-type {
case mpls {
description "The BIER forwarding depend on mpls.";
}
case non-mpls {
description "The BIER forwarding depend on non-mpls.";
}
case ipv6 {
description "The BIER forwarding depend on IPv6.";
}
description "The encapsulation type in BIER.";
}
leaf bitstringlength {
type uint16;
description "The bitstringlength used by BIER forwarding.";
}
leaf set-identifier {
type si;
description "The set identifier used by this multicast flow.";
}
leaf ecmp {
type boolean;
description "The capability of ECMP.";
}
leaf frr {
type boolean;
description "The capability of fast re-route.";
}
}
grouping transport-bier-te {
description "The BIER-TE transport information.";
leaf sub-domain {
type sub-domain-id;
description "The subdomain id that this multicast flow belongs to.";
}
choice encap-type {
Zhang, et al. Expires February 22, 2018 [Page 12]
Internet-Draft Multicast Model August 2017
case mpls {
description "The BIER-TE forwarding depend on mpls.";
}
case non-mpls {
description "The BIER-TE forwarding depend on non-mpls.";
}
description "The encapsulation type in BIER-TE.";
}
leaf bitstringlength {
type uint16;
description "The bitstringlength used by BIER-TE forwarding.";
}
leaf set-identifier {
type si;
description "The set identifier used by this multicast flow, especially in BIER TE.";
}
leaf ecmp {
type boolean;
description "The capability of ECMP.";
}
leaf frr {
type boolean;
description "The capability of fast re-route.";
}
}
grouping transport-pim {
description "The requirement information of pim transportion.";
leaf graceful-restart {
type boolean;
description "If the graceful restart function should be supported.";
}
leaf bfd {
type boolean;
description "If the bfd function should be supported.";
}
}
grouping mldp-tunnel-feature {
description "The tunnel feature.";
leaf mldp-tunnel-id {
type uint32;
description "The tunnel id that correspond this flow.";
}
leaf mldp-frr {
type boolean;
description "If the fast re-route function should be supported.";
}
Zhang, et al. Expires February 22, 2018 [Page 13]
Internet-Draft Multicast Model August 2017
leaf mldp-backup-tunnel {
type boolean;
description "If the backup tunnel function should be supported.";
}
}
grouping p2mp-te-tunnel-feature {
description "The tunnel feature.";
leaf te-tunnel-id {
type uint32;
description "The tunnel id that correspond this flow.";
}
leaf te-frr {
type boolean;
description "If the fast re-route function should be supported.";
}
leaf te-backup-tunnel {
type boolean;
description "If the backup tunnel function should be supported.";
}
}
/*typedef sub-domain-id {
type uint16;
description
"The type for sub-domain-id";
}*/
grouping transport-mpls {
description "The mpls transportion information.";
choice mpls-tunnel-type {
case mldp {
uses mldp-tunnel-feature;
description "The mldp tunnel.";
}
case p2mp-te {
uses p2mp-te-tunnel-feature;
description "The p2mp te tunnel.";
}
description "The collection types of mpls tunnels";
}
}
grouping cisco-multicast {
description "The Cisco MDT multicast information in RFC6037.";
leaf p-group {
type inet:ip-address;
description "The address of p-group.";
Zhang, et al. Expires February 22, 2018 [Page 14]
Internet-Draft Multicast Model August 2017
}
}
grouping transport-cisco-mode {
description "The transport information of Cisco mode, RFC6037.";
uses cisco-multicast;
uses transport-pim;
}
grouping multicast-transport {
description "The transport information of multicast service.";
container bier {
uses transport-bier;
description "The transport technology is BIER.";
}
container bier-te {
uses transport-bier-te;
description "The transport technology is BIER-TE.";
}
container cisco-mode {
uses transport-cisco-mode;
description "The transport technology is cisco-mode.";
}
container mpls {
uses transport-mpls;
description "The transport technology is mpls.";
}
container pim {
uses transport-pim;
description "The transport technology is PIM.";
}
}
/*underlay*/
grouping underlay-bgp {
description "Underlay information of BGP.";
}
grouping underlay-ospf {
description "Underlay information of OSPF.";
leaf topology-id {
type uint16;
description "The topology id of ospf instance.";
}
}
grouping underlay-isis {
description "Underlay information of ISIS.";
Zhang, et al. Expires February 22, 2018 [Page 15]
Internet-Draft Multicast Model August 2017
leaf topology-id {
type uint16;
description "The topology id of isis instance.";
}
}
grouping underlay-babel {
description "Underlay information of Babel.";
/* If there are some necessary information should be defined? */
}
grouping underlay-pim {
description "Underlay information of PIM.";
/* If there are some necessary information should be defined? */
}
grouping multicast-underlay {
description "The underlay information relevant multicast service.";
leaf underlay-requirement {
type boolean;
description "If the underlay technology should be required.";
}
container bgp {
uses underlay-bgp;
description "The underlay technology is BGP.";
}
container ospf {
uses underlay-ospf;
description "The underlay technology is OSPF.";
}
container isis {
uses underlay-isis;
description "The underlay technology is ISIS.";
}
container babel {
uses underlay-babel;
description "The underlay technology is Babel.";
}
container pim {
uses underlay-pim;
description "The underlay technology is PIM.";
}
}
container multicast-information {
description "The model of multicast service. Include overlay, transport and underlay.";
list multicast-info{
Zhang, et al. Expires February 22, 2018 [Page 16]
Internet-Draft Multicast Model August 2017
key "vpn-id source-address source-wildcard group-address group-wildcard vni-type vni-value";
uses multicast-feature;
description "The detail multicast information.";
container multicast-overlay {
description "The overlay information of multicast service.";
uses multicast-overlay;
}
container multicast-transport {
description "The transportion of multicast service.";
uses multicast-transport;
}
container multicast-underlay {
description "The underlay of multicast service.";
uses multicast-underlay;
}
}
}
}
<CODE ENDS>
6. Notifications
TBD.
7. Acknowledgements
The authors would like to thank Stig Venaas, Jake Holland for their
valuable comments and suggestions.
8. Normative References
[I-D.ietf-bier-architecture]
Wijnands, I., Rosen, E., Dolganow, A., Przygienda, T., and
S. Aldrin, "Multicast using Bit Index Explicit
Replication", draft-ietf-bier-architecture-07 (work in
progress), June 2017.
[I-D.ietf-bier-bier-yang]
Chen, R., hu, f., Zhang, Z., dai.xianxian@zte.com.cn, d.,
and M. Sivakumar, "YANG Data Model for BIER Protocol",
draft-ietf-bier-bier-yang-02 (work in progress), August
2017.
Zhang, et al. Expires February 22, 2018 [Page 17]
Internet-Draft Multicast Model August 2017
[I-D.ietf-pim-yang]
Liu, X., McAllister, P., Peter, A., Sivakumar, M., Liu,
Y., and f. hu, "A YANG data model for Protocol-Independent
Multicast (PIM)", draft-ietf-pim-yang-08 (work in
progress), April 2017.
[RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for
the Network Configuration Protocol (NETCONF)", RFC 6020,
DOI 10.17487/RFC6020, October 2010, <https://www.rfc-
editor.org/info/rfc6020>.
[RFC6037] Rosen, E., Ed., Cai, Y., Ed., and IJ. Wijnands, "Cisco
Systems' Solution for Multicast in BGP/MPLS IP VPNs",
RFC 6037, DOI 10.17487/RFC6037, October 2010,
<https://www.rfc-editor.org/info/rfc6037>.
[RFC6087] Bierman, A., "Guidelines for Authors and Reviewers of YANG
Data Model Documents", RFC 6087, DOI 10.17487/RFC6087,
January 2011, <https://www.rfc-editor.org/info/rfc6087>.
[RFC6513] Rosen, E., Ed. and R. Aggarwal, Ed., "Multicast in MPLS/
BGP IP VPNs", RFC 6513, DOI 10.17487/RFC6513, February
2012, <https://www.rfc-editor.org/info/rfc6513>.
[RFC7223] Bjorklund, M., "A YANG Data Model for Interface
Management", RFC 7223, DOI 10.17487/RFC7223, May 2014,
<https://www.rfc-editor.org/info/rfc7223>.
Authors' Addresses
Zheng Zhang
ZTE Corporation
No. 50 Software Ave, Yuhuatai Distinct
Nanjing
China
Email: zhang.zheng@zte.com.cn
Cui(Linda) Wang
ZTE Corporation
No. 50 Software Ave, Yuhuatai Distinct
Nanjing
China
Email: lindawangjoy@gmail.com
Zhang, et al. Expires February 22, 2018 [Page 18]
Internet-Draft Multicast Model August 2017
Ying Cheng
China Unicom
Beijing
China
Email: chengying10@chinaunicom.cn
Zhang, et al. Expires February 22, 2018 [Page 19]
