© copyright 1997, the university of new mexico e-1 internetworking technologies & services...

E-1© Copyright 1997, The University of New Mexico

Internetworking Technologies & Services (III)

• Introduction to The Internet• Internet 2• vBNS• NGI• Routing/Futures


IPv6

• Solves IPv4 address limitation by extending addressing from 32 to 128 bits

• Improved option mechanism• Address auto-configuration • Support for resource allocation• Enhanced Security Capabilities• Provider-based unicast addresses • Site-local-use addresses • Link-local-use addresses


IPv6


Internet Evolution


Internet Evolution

• In 1958, the Advanced Research Projects Agency (ARPA) of the Department of Defense (DoD) was created. The purpose of the government agency was to foster technology and was partially in response to the Sputnik launch by the USSR.


Internet Evolution

• 1969 - DoD formed a computer network for ARPA and gave it the name ARPANET. The network was designed to help government scientists communicate and share information. It was originally developed to allow researchers to log-in and run programs on remote computers, but it quickly became a tool for sharing information through file transfer, electronic mail, and interest group mailing lists.


Internet Evolution

• 1970 - ARPA became the Defense Advanced Research Projects Agency (DARPA) and ARPANET became DARPANET.

• 1980 - DARPANET had grown and other networks were being developed. The architects recognized that they needed new communication protocols for the network. This led to the development of a new architecture and protocol suite called TCP/IP.


Internet Evolution

• 1983 - DARPANET split into DARPANET and MILNET (Military Network). The Internet was formed when the Defense Communications Agency, which managed both networks, mandated the use of TCP/IP for all hosts connected to either network.


Internet Evolution

• 1986 - National Science Foundation (NSF) joined Internet. The NSF created NSFNET to link several national supercomputer centers to support scholarly research. The NSFNET backbone of Internet now comprises 17 networks, connecting to 23 midlevel wide-area networks across the continent. In turn, the midlevel networks link computers in more than 1000 university, government, and commercial research organizations throughout the world.


Internet Evolution

• 1990 - ARPANET was dismantled. NSFNET and MILNET are now the backbone for Internet, carrying the burden of the traffic on 56 kbps or T1 1.5 mbps transmission lines. NSFNET is currently increasing its speed to 45 mbps. Since the creation of Internet, the number of connected networks has increased rapidly. Recent estimates suggest the number of hosts range up to 1,000,000, and the number of users ranges from seven to ten million.


56 Kbps NSFNET Backbone


448 Kbps NSFNET Backbone


T1 NSFNET Backbone


T3 NSFNET Backbone


NSFNET Old Architecture


NSFNET New Architecture


ANSNET


International Internet Connectivity


Internet Popularity - BSD Unix

• Internet was the implementation of the TCP/IP for the Berkeley Software Distribution (BSD) of the Unix operating system, which was and is in use at approximately 90 percent of all university computer science departments in the United States.


Internet Popularity - Free

• No charges per user or per message. Once a physical connection has been made, no charges are incurred for usage or on-line time except in special cases. The local telecommunication company or service provider may charge an installation and line fee, and line usage charges, but use of the Internet is free.


Internet Futures

• Current trends indicate that Internet access will be even more important in the business world, and with lower access costs.

• The National Information Infrastructure: Agenda for Action, which stresses government involvement with the private enterprise to construct a seamless web of communications networks, computers, databases, and consumer electronics that will put vast amounts of information at users fingertips. The pace of Internet expansion is rapidly quickening.


Internet Hosts


Internet Domain Names


Internet Host Stats


Internet Hosts Stats


Internet Hosts


Sample Internets

• DREN• NASA


DREN


NASA National Internet


NASA International Internet


vBNS


vBNS

• vBNS stands for Very high speed Backbone Network Service.

• It is the Internet fast lane for Research and Education.

• It is a high performance network service.– Sponsored by NSF (National Science Foundation).– Implemented by MCI.


Evolution of vBNS

• Internet was initially developed for interconnection of research institutes, later it was commercialized.

• It was a big success and led to traffic congestion.

• To ensure continuos availability of high performance network for R&E ( Research and Education) community NSF established vBNS through a cooperative agreement with MCI.


Implementation of vBNS

• First activated on a test basis in late 1994.

• It’s full network topology was on-line in early 1995.

• It was first implemented as an IP/ATM network with an OC-3 (155 Mbps) infrastructure.

• vBNS backbone is currently being upgraded to OC-12 ( 622 Mbps ) speeds.


vBNS Backbone Topology


Architecture Overview

• vBNS interconnects 5 SCCs ( Super computer centers ) and 4 NAPs ( Network access points ) .

• The 5 SCCs are – Cornell Theory Center (CTC) Sprint - New York .– National Center for Atmospheric Research (NCAR) MFS

- Washington DC .– National Center for SuperComputer Applications

(NCSA) Ameritech - Chicago .


Architecture Overview (contd.)

– Pittsburgh SuperComputer Center (PSC) Pacific Bell - San Francisco .

– San Diego SuperComputer Center (SDSC).

• Each SCCs has identical suite of equipment for network access.


Network access

• Each SCC has network access via– routed FDDI.– routed HIPPI.– ATM UNI.

• WAN connectivity is via through 1 or 2 OC-3 connections to ATM WAN.


vBNS SCC Architecture


Standard equipment at SCC site

• IP over FDDI is supported by – NetStar GigaRouter – Cisco 7507.

• IP over HIPPI is supported by – NetStar GigaRouter.

• The design includes 2 routers – CISCO because well known and reliable.– GigaRouter because it supprts HIPPI and offers

potential growth to OC-12.


Standard equipment at SCC site (contd.)

• Cell level ATM is supported by the FORE ASX-1000.– This enables compatibility between IP packets and ATM

cells.– To enable connectivity to ATM WAN network.


Links to other R&E institutions

• R&E institutions are linked to vBNS Via a – NAP ( Network Access Point) or– Private interconnect at DS3 (45 Mbps) speed or– Private interconnect at OC-3 (45 Mbps) speed.

• All connections support IP.• Some connections support ATM.


Backbone of vBNS

• MCIs commercial ATM network is being used as the backbone of vBNS network.

• The commercial ATM network has an OC-3 backbone .

• vBNS is the only network which has OC-3 access rate.


vBNS Traffic Flow

• vBNS traffic flows over a set of PVPs ( Permanent Virtual paths ) of MCIs commercial ATM network.

• Dedicated ATM switches ( FORE ASX 1000s and LightStream 2020s ) are used for switching vBNS traffic.

• These dedicated switches are co-located with commercial backbone switches.


vBNS Traffic Flow

• The vBNS PVPs traverse the shared commercial backbone.

• They donot merge at commercial switches.

• PVPs run from one vBNS dedicated ATM switch to it neighbor.

• This kind of switching is achieved by using PVCs (Permanent Virtual Circuits).


vBNS Traffic Flow

• By using PVPs and dedicated switches, vBNS backbone can be perceived as – logically connected ATM network of its own.– logically connected through a set of dedicated Atm

switches.


PVPs of vBNS


ATM services provided to vBNS

• Variable Bit Rate (VBR) service is utilized so that bandwidth may be dedicated to the vBNS' PVPs.

• The service is configured with a Peak Cell Rate (PCR) equal to OC-3 line rate.

• This configuration is ideally suited to support the bursty nature of the traffic that is carried over the vBNS.


Performance

• Performance tests between hosts at different SCCs demonstrated peak rates for UDP traffic of 133 Mbps.

• After discounting the cell tax (ATM overhead) this is very close to the possible IP over OC-3 ATM maximum of 135 Mbps.


Switching IP over ATM

• Switching IP traffic over the vBNS' dedicated PVPs is accomplished by using two meshes of PVCs.– One mesh of PVCs support "point to point" links

between IP routers over which IP routing protocols are run.

– Second mesh supports a Logical IP Subnet (LIS) as well as non-IP ATM traffic.



• Point to Point PVCs– These provide a full mesh of interconnections between

vBNS ATM connected routers (almost all).– Several routers are connected with a second backup

PVCs.– The mesh of PVCs is utilized by the routers as mesh of

point to point circuits. – It is a flat architecture and each router is only one hop

away from every other router.



– OSPF is used as IGP (Interior Gateway Protocol), which enables the routers to share the information about link costs and outages.

– Unless there is an outage lowest cost PVC joining any two routers is used.

– Incase of outage a backup PVC is used if available.– Otherwise alternate route is choosen using the

information provided by OSPF. At IP layer this route will appear as 2 or more hops long.



• LIS PVCs– These also provide a full mesh of interconnections

between vBNS ATM connected routers.– The mesh’s end points also include additional ATM

ports at the SCCs.– Devices attached to these ATM ports can use IP to

communicate with other members of the LIS.– They can also use the PVCs to exchange non IP traffic

with other ATM connected devices.



• LIS PVCs ( contd.)– With equipment upgrade LIS PVC mesh can be replaced

with SVCs ( Switched Virtual Circuits ).– Using SVC instead of PVCs network complexity is

reduced.– It also increases the network robustness.


Exterior Gateway Protocol (EGP)

• BGP4 is used as an EGP.• BGP peering sessions between vBNS

routers and routers at SCCs and R&E institutions are used to exchange routing information.

• Full internet routing to vBNS backbone routers is supported via BGP peering with internetMCI routers at the NAPs.


Utilization of vBNS resources

• NSF has established an Appropriate Use Policy (AUP) for the vBNS in order to ensure that the vBNS' resources are dedicated to and available for the community it serves the .

• The AUP is implemented on the vBNS using BGP communities.


Utilization of vBNS Resources

• Two BGP communities have been set up: – primary peers, which include the 5 SCCs and other NSF

specified R&E institutions.– secondary peers, which include other networks that

support R&E institutions such as ESnet (a Department of Energy network) and the NASA Internet.

• Primary peers are given all the routes the vBNS gets from both primary peers and secondary peers.


Utilization of vBNS Resources

• Secondary peers are given only the routes the vBNS gets from primary peers.

• This scheme ensures connectivity between primary peers and between primary and secondary peers.

• It prevents secondary peers from using the vBNS for transit.


Current vBNS BGP Peers


vBNS Testnet

• To offer state of the art services, the vBNS cooperative agreement specifies the introduction of– new hardware,– new protocols, and– new transmission technologies into the network as

they become available.

• The vBNS Testnet is deployed as a platform for preoperational testing.


vBNS Testnet

• It is used to validate any planned changes to the vBNS network.

• It serves as a platform for experimenting with and gaining experience in new technologies.

• Its main users are members of MCI's Internet Technology group.

• It is available for SCC network researchers to conduct experiments and tests that are potentially disruptive to the operation of the vBNS.


vBNS Testnet

• The Testnet has stayed one step ahead of the vBNS. Originally it was a network consisting of DS-3 and OC-3 links carrying IP over ATM.

• Today it is an OC-3/OC-12 network with OC-12 links connecting nodes located at SDSC; PSC; and an MCI lab in Richardson, TX, and an OC-3 link connecting to a node located at an MCI lab in Reston, VA.


vBNS Acceptable Usage policies

• vBNS Authorized Institutions (vAIs) are defined as U.S. research and education institutions which are approved to use the vBNS by the NSF's Division of Networking and Communications Research and Infrastructure.

• vBNS Partner Institutions (vPIs) are organizations with which vAIs need to interact.



• VPIs include such organizations as – Federal research laboratories,– Research and education institutions in other countries

or – Firms which have been approved for either a direct

connection to the vBNS or an interconnection with the vBNS via (an)other research network(s) by NSF's Division of Networking and Communications Research and Infrastructure .



• vAIs may utilize the vBNS to exchange traffic among themselves and to exchange traffic with vPIs.

• vPIs may utilize the vBNS to exchange traffic with vAIs but may not utilize the vBNS to exchange traffic with each other.

• Neither vAIs nor vPIs may use the vBNS to exchange traffic with institutions or organizations which have not been specifically authorized or approved to utilize the vBNS by NSF.


vBNS Acceptable Usage Policies

• All vAIs and vPIs must maintain non-vBNS connectivity sufficient to support all of their networking requirements which fall outside of the approved uses of the vBNS.

• NSF, the vBNS provider, vAIs and vPIs will jointly develop and implement methodologies and architectures to route traffic as necessary in support of this policy.


Internet2 Project

• The Internet2 project is a collaborative effort among– a number of universities,– federal R&D agencies, and – private sector firms to develop a next generation

Internet for research and education, including both enhanced network services as well as the multimedia applications which will be enabled by those services.


Objectives

• The technical objectives of Internet2 are:– Maintain a common bearer service to support new and

existing applications, – Move from best effort packet delivery to a

differentiated communications service,– Provide the capability of tailoring network service

characteristics to meet specific applications requirements, and

– Achieve an advanced communications infrastructure for the Research and Education community.


Applications Requirements

• Within and across many universities, a set of advanced network based applications are emerging, these will greatly enrich teaching, learning, collaboration and research activities.

• Some of the applications are– The broad use of distance learning will require

selectable quality of service and efficient "one-to-many" data transport in support of multimedia and shared information processing.



– Leading-edge research community needs high capacity and selectable quality of service to make effective use of national laboratories, computational facilities and large data repositories.

– Medical researchers need support for remote consultation and diagnoses over highly reliable and predictable communications services.

– Physical scientists, especially those who deal with massive astronomical or geophysical datasets, have similar needs.



– As transaction-level commercial data come into research focus, financial and economic analysts will need real-time access to masses of data.

• A major impediment to the realization of these applications is lack of advanced communications services in the current commodity Internet.


Application Requirements Proposed Solutions

• Internet 2 seeks to enable these new applications.

• It will do so by working with the information technology industry to develop common standards and support services for new classes of applications.

• It will ensure the availability of the advanced communication services required.


Other Communication Requirements

• Other research, educational, and government communities face application and communications needs very similar to those within higher education.

• These needs have spawned several high-performance networking initiatives that variously parallel and overlap Internet 2, especially the NSF vBNS project and the set of "Next Generation Internet" efforts announced by the White House last fall.


Co-existence of different networks

• Internet 2 is intended to develop in concert with these other efforts, thereby – gaining synergy,– minimizing duplication,– maximizing compatibility and – interoperability among the resulting networks and

applications.


Issues in design of Internet 2

• It is important that the I2 design be flexible enough to accommodate both – currently anticipated requirements as well as– new requirements as they become known.

• Fundamental to the Internet 2 infrastructure design is maintenance of a "common bearer service" for communication among network applications.


Issues in design of Internet 2

• The "bearer service" is the basic information transport interface for wide area communications, analogous to layer 3 in the ISO network model.

• One of the greatest strengths of the existing Internet is the ability of any node to communicate with any other node in a compatible transport format.

• In Internet 2 this strength must be preserved to the extent possible.


Issues in design of Internet 2 (contd.)

• The I2 bearer service must be backwards compatible with the existing commodity Internet.

• The existing infrastructure will continue to be the access path to all non-participants in Internet 2.


Internet2 Architecture



• The key new element in the I2 architecture is the GigaPOP.

• GigaPOP is a high capacity, state of art interconnection point.

• It is the point where I2 participants may exchange advanced services traffic with other I2 participants.

• Campuses in a geographic region will join together to acquire a variety of internet services at a regional GigaPOP.



• Each campus will install a high speed circuit to its choosen GigaPOP

• The campus gains access to the commodity internet services and the advanced Internet 2 services through the GigaPOP to which it is connected.

• The various GigaPOPs join together to acquire and manage connectivity among themselves.

• Initially the interconnect between GigaPOPs will be most likely be provided by NSFs vBNS.


Technical components

• Internet 2 has four major technical components – Applications that require I2-level services and the

equipment end users need to run the applications (denoted by solid-colored screens in Figure for overall architecture of I2).

– Campus networks connecting GigaPOPs to end users in their labs, classrooms, or offices (solid clouds).

– GigaPOPs consolidating and managing traffic from campus networks (striped clouds) and

– I2 interconnections among the GigaPOPs (dotted cloud).


GigaPOPs

• Equipment at a GigaPOP site will include:– One or more very high capacity advanced function packet

data switch/routers capable of supporting at least OC-12 (622 megabit/second) link speeds and switched data streams as well as packet data routing.

– Switch/routers supporting Internet Protocols (both version 4 and the new version 6), advanced routing protocols such as MOSPF, and “quality of service” protocols such as RSVP.

– SONET or ATM multiplexers to enable allocation of link capacity to different services such as highly reliable IP packet delivery, experimental testbeds for emerging protocols, or special requirements determined by new initiatives among the Internet2 member institutions; and


GigaPOPs

– Traffic measurement and related data gathering to enable project staff to define flow characteristics as part of the operational and performance monitoring of the GigaPOPs.


Communication services at GigaPOP

• One or more wide area communications service providers will connect to the GigaPOPs – To provide communications paths between the nationwide

set of GigaPOPs and

– between GigaPOPs and the established commercial Internet.

• The participating institutions will acquire a wide variety of commercial as well as pre-competitive communications services over a single high capacity communications link to the nearest GigaPOP facility.


Structure and Services

• Logically, a gigapop is a regional network interconnect point providing access to the inter-gigapop network for (typically) several I2 members.

• Physically, a gigapop is a secure and environmentally conditioned location that houses a collection of communications equipment and support hardware.



• Circuits terminate there both from Internet 2 members' networks and from wide-area data-transport networks both I2 and commercial.

• I2 members' networks are non-transit networks, that is, they don't carry traffic between a gigapop and the general Internet.

• GigaPOPs will serve end-user non-transit networks through appropriate IP route management.



• I2 gigapops will not serve commercial transit networks, nor is peering allowed among such networks via the gigapop routing infrastructure.

• Inter-gigapop links will ONLY carry traffic among Internet 2 sites.

• A gigapop's key function is the exchange of I2 traffic with specified bandwidth and other Quality of Service attributes.


Access to other networks

• In addition to the I2 traffic, standard IP traffic can be exchanged with commodity Internet service providers that have a termination at the gigapop.

• This eliminates the need for separate high speed connections between the participant's campus network and other ISP exchange points.

• Some of the networks to which gigapop may link I2 campus are


Access to other networks

– Other metropolitan area networks in their communities, for example to provide local distance education.

– Research partners and other organizations with which I2 members wish to communicate.

– Other dedicated high-performance wide area networks, for example those that the government implements for its own research units and

– Other network services, for example commodity Internet backbone providers.


GigaPOP configuaration

ATM Switching Elements

IPRouting Elements

I2 Campus connections ( ATM )

I2 Campus connections ( Non ATM )

Commercial ATM access

vBNS

Dedicated Connections

Regional or State Networks

ISP / NSP Links

Urban Area Network Service

An I2 gigapop does route traffic amongI2 Campuses and to other I2 gigapops

An I2 gigapop does not route traffic amongnon I2 networks and providers


Categorization of GigaPOPs

• GigaPOPs can be broadly classified as 2 types– Type I gigapops, which are relatively simple, serve only

I2 members, route their I2 traffic through a one or two connections to another gigapops, and therefore have little need for complex internal routing and firewalling.

– Type II gigapops, which are relatively complex, serve both I2 members and other networks to which I2 members need access, have a rich set of connections to other gigapops, and therefore must provide mechanisms to route traffic correctly and prevent unauthorized or improper use of I2 connectivity.


Categorization of GigaPOPs

• In the figure shown for configuration of gigapop for type 1 gigapops the connections to other services will be omitted.

• For type 2 giagapops enough care must be taken to isolate I2 traffic with other kinds of traffic and also care must be taken to not to allow non IP traffic over I2 inter gigapop conections.


Functional Requirements

• Protocols– Since the common bearer service for I2 is IP, all layer 3

devices support • IPv4• IPv6 ( as soon as the stable implementations for this are available )

– IGMP ( Internet Group Management protocol, a protocol which supports multicast).

– RSVP ( which supports resource reservations ).



• Speed:– The bit rate of connections into a gigapop or between

gigapops will vary widely, depending on the number and intensity of the I2-based applications running on its member campuses.

– The issue for the gigapop itself is to make sure that it has adequate capacity to handle the anticipated traffic load.

– The switches providing the primary interconnectivity in a gigapop, and the links from those switches to adjacent gigapop routers should be sized so that packet loss within the gigapop is near zero.



• Linkage:– Initial layer-2 connectivity to other gigapops is

expected to utilize ATM PVCs from the vBNS plus some dedicated links that may be ATM PVCs or SVCs, or raw SONET links.

– The linkages among gigapop routers connected to wide-area links will typically be provided by high-performance switches, typically either a cell-based or a frame-based service, depending on the needs of each specific gigapop.



• Collaborations among gigapops:– Although multi-QoS and multicast connectivity among all

Internet 2 members is an explicit and important goal of the project, not all I2 members will be involved in every advanced application experiment

– Some of these experiments will involve institutions served by a single gigapop .

– A likely scenario will be for several gigapops to collaborate on specific application experiments and other projects.



– For example, multiple gigapops might work together with private enterprise to facilitate improved connectivity for asynchronous and distance learning from member institutions to their constituents homes, just as gigapops may facilitate local traffic exchange among commodity Internet Service Providers in their region.


Operational Responsibilities

• Because of the end-to-end nature of I2, operation of the network will require more coordination between network operators and between network operators and end users in most parts of the Internet.

• This coordination should be automated to the greatest extent possible.

• The current Internet lacks the tools and protocols to manage multiple levels of service.


Operational Responsibilities

• One I2 objective will be to work with standards bodies and developers to create these protocols and tools.

• In the development of these protocols and tools it must be kept in mind that they will eventually be used in the commercial Internet, which operates in a different trust and sharing environment than the academic community.


The basic I2 communications infrastructure


Connectivity

• Connectivity has to be dealt in 2 places in the network architecture of Internet2.

– Connection between end user applications and campus GigaPOP.

– Interconnection between GigaPOPs.


Campus networks

• Campus networks must be able to provide adequate support for advanced applications.

• Campus network must be able to support applications requiring – high bandwidth– low latency– low jitter– multicasting


Campus networks

• Different campuses may make different decisions on how to achieve the requirements. Implementation may be – Cell switching backbones.– Frame based ethernet solutions.– RSVP or other IP bandwidth reservation techniques.

• Upgrade of campus network is the significant expense of I2 member’s I2 investment.


Campus to GigaPOP

• I2 campus will require high capacity circuits to the nearest gigapop.

• They require advanced-functionality routers as their campus gateways.

• Campuses wishing to support additional services might install an ATM multiplexer or switch between the gigapop connection circuit and the campus border.


Campus to GigaPOP

• Campus to gigapop connection will carry less traffic than inter gigapop connection.

• The non-I2 traffic may exist on campus to gigapop connection.

• In some places there are no commercially available or financially feasible ways to reach I2 campus to gigapop connection quality levels yet, in these cases I2 bandwidth and selectable QoS will not be available to the campuses until the problem is solved.


Gigapop-to-Gigapop

• The key features that interconnection between gigapops should provide are – Very high reliability.– High capacity ( bandwidth).– Support for selectable QoS, and– Data-collection and circuit management tools.


Gigapop to Gigapop connectivity

• The initial form of connectivity is expected to be NSF vBNS network.

• Other possible linkages include – national network clouds , Sprint’s or IBM’s.– a national network created and operated by I2.– Individual point to point links between cooperating

gigapops.


Routing

• Internet 2 will only be used by I2 members as a transit network to reach – other I2 members.– Other special research networks.

• A Consortium of I2 members can establish to commercial internet, and other services for its own purposes, but will not propagate any information received from them into Internet 2.


Quality of Service

• I2 is expected to permit requests for at least 5 dimensions of QoS

• Transmission speed: The minimum effective data rate to be provided, plus perhaps a target average and a tolerable maximum limit. Thus, for example, a user might request a connection whose data rate never falls below 50Mbps, and agrees not to expect transmission faster than 100Mbps.


Quality of Service

• Bounded delay and delay variance.– Especially for video and other signals that carry real-

time information, the maximum effective interruption allowed. A user might specify that there be no gap between packets long enough to interrupt or freeze live video.

• Throughput.– The amount of data to be transmitted in a specified

time period. A user might specify that a terabyte of data be moved within ten minutes.


Quality of Service

• Schedule.– The starting and ending times for the requested

service. A user might specify that the requested connectivity be available at some exact time in the future for some specified period (which of course would arise from the other QoS specifications).

• Loss rate.– The maximum packet loss rate to be expected within a

specified time interval.


Network Services

• For example, in order to support delivery of advanced multimedia teaching materials from a digital library repository to a dispersed audience of learners, it will be necessary for the service delivery infrastructure to support "multicast" data delivery with guaranteed upper bounds within the transport components on delay and data loss.


Protocols for the Network services

• New protocols for the above network services have already been defined and will be deployed early in the Internet2 project.

• These protocols include the IETF defined quality of service protocols such as RSVP and RTP along with IPv6, the IETF-developed replacement for the version of IP that is in current use on the Internet.

© copyright 1997, the university of new mexico e-1 internetworking technologies & services...

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