Internet 2

Table of Contents

1. Introduction

2. Internet2 project overview

2.1 Organisation of I2 project

3. Internet 2 infrastructure

3.1 Topology

3.2 What is gigapop?

3.2.1 Gigapop connections

3.2.2 Gigapop functional requirements

3.2.3 Routing between gigapops

3.2.4 Gigapop example

3.3 I2 Connectivity cloud

3.4 Local networks

3.4.1 Example: upgrade at University of Central Florida

4. Internet 2 network services

4.1 Quality of service

4.2 Multicast

4.3 Measurement and optimization

4.4 Network management

4.5 Security

4.6 Network storage

5. Internet 2 applications

5.1 Application architecture concepts

5.1.1 Technical requirements for Internet 2 applications

5.1.2 Important architectural concepts

5.2 Application types

5.2.1 Learningware

5.2.2 Digital libraries

5.2.3 Tele-immersion

5.2.4 Virtual laboratory

5.3 Application development schedule

5.4 Application example: Provably Secure Videoconferencing

6. Conclusions

7. Glossary

References

1. Introduction

Behind this joint effort of U.S. universities was concern for the situation of current Internet. Public, commercial and congested Internet was not able to offer support for the research community as it had done for several years since 1987 when NFSnet was established.

It was also seen in universities that the current Internet was not able to offer network services sophisticated enough to carry data in broadband networks where media integration, interactivity and collaboration are among the largest application centric traffic areas. Therefore one of the objectives of the I2 project was to set up a large testbed, partly isolated from the public Internet, where new types of network services and applications could be tested. An as soon as proven feasible, I2 project believed that universities could catalyze in transfer new services and applications to educational use as well as to corporations and homes.
 

To date over 120 U.S. universities take part in the I2 project. Among the corporate partners of the I2 project are for example 3Com, AT&T, Cisco Systems, IBM and MCI. Among corporate members and sponsors are e.g. Alcatel, Apple, Digital Equipment Corporation and Nokia. The I2 project is also closely related to U.S. federal network projects such as Next Generation Internet -project (NGI), which aims at developing advanced network technologies.

University members of I2 project are funding the project by over $50 million per year and corporate partners are committed to providing almost $20 million during the project [1]. Federal agencies and organisations participating NGI initiative are also funding the project.

2. I2 Project Overview

At the early phases of the project the emphasis is on developing the network capability required by the research community. Besides increased network bandwidth targets set for network infrastructure include for example differentiated quality of service (QoS) determined by application requirements. Network equipment developed within the I2 project scope is encouraged to be deployed later in the public Internet. This goal implies that solutions developed should also be affordable in order to guarantee widespread use of infrastructure technologies.

Main focus of the I2 project is on applications. Capabilities of broadband network are exploited by developing applications that support research objectives, media integration, real time collaboration, distance education to name a few [2]. Along with applications common middleware framework and development tools are developed in order to facilitate and catalyze the application development in broadband environment both in member organisations and later on publicly.

The I2 project will be conducted in several phases during the following couple of years. To date the project has made surveys and studies on how infrastructure should be built in order to serve applications in the best way. Parts of the infrastructure have been built, there is approximately twenty operational gigapops, which is a term meaning a network point connecting local network to backbone network. Gigapop stands for gigabit point of presence.

2.1 Organisation of the I2 project

For more detailed level the I2 project is divided into working groups. Working groups work on specific areas, which relate to the goals of the I2 project. Currently there are the following working groups:

• IPv6
• Measurement
• Multicast
• Network Management
• Network Storage
• Quality of Service
• Routing
• Security
• Topology

3. I2 Infrastructure

3.1 Topology

Each campus or research entity taking part in I2 will install a high speed circuit from their local networks (referred to as Intra-Campus connectivity in I2 parlance) to a chosen gigapop (Campus-to-Gigapop). One gigapop will provide service for several campuses or organisations. 5-10 organisations can connect to one gigapop, depending on the size of the organisation.

Traffic between organisations connected to one gigapop is called Intra-Gigapop traffic and it can be routed or switched within the gigapop's equipment. Gigapop-Gigapop connections construct the Connectivity Cloud shown in Figure 3.1 which is the wide area part of I2. Each of these three elements is discussed in more detail below.

3.2 What is Gigapop?

3.2.1 Gigapop connections

• Type 1: Simple, serves only I2 members and routes their traffic to other gigapops. Little requirements for complex internal routing or firewalling etc.
• Type 2: Complex, serves both I2 members and other networks to which I2 members need access, connects to several other gigapops. Need routing policies as well as authorization mechanisms.

ATM switching element shown in the middle of Figure 3.2 may connect with direct SONET circuits to campus ATM switches or to other gigapops. Connections may also be full ATM service from commercial providers. ATM switching elements multiplex with either switched virtual circuits (SVC) or with permanent virtual circuits (PVC) depending on the characteristics of the connection. ATM switching element allows optimization and separate bandwidth allocation for I2 testbed traffic and production traffic [4] or for other requirements.

IP routing element shown in Figure 3.2 provides the primary service of a gigapop. It makes all decisions concerning QoS support or IP routing. IP routing element can feed traffic directly to/from SONET/PPP, high speed synchronous circuit or PVC/SVC links into ATM fabric.

3.2.2 Gigapop functional requirements

• Supported protocols
• Since common bearer service of I2 is IP, all network layer devices must support IP. However, though IPv4 is the current standard of IP, it is assumed that I2 project can help in the emergence of IPv6. Therefore gigapops must support both IPv4 and IPv6 as soon as stable implementations of the latter are available. Also other protocols of TCP/IP family are to be supported, including multicast support protocols like IGMP (Internet Group Management Protocol) and RSVP (Resource Reservation Setup Protocol).
• Routing
• Gigapops must be responsible for either allowing or denying packet flow via certain link. This requirement is discussed in more detail in section 3.2.3
• Speed
• Bit rates to and from gigapop may vary. Gigapops have to be sized in a manner that enables minimal packet loss within gigapop.
• Linkage
• Layer 2 connectivity must support ATM PVC/SVC links as well as raw SONET links.
• Costing and use measurement
• Gigapops have to be able to save and share usage statistics for cost allocation between I2 members.
• Enable hierarchical aggregation
• If necessary it should be possible to aggregate gigapops to form hierachical structures. This allows capacity scaling whenever required.
• Technology transfer
• Gigapops should be designed in manner that enables upgrading to new technologies. This requires communication between gigapop operators.

3.2.3 Routing between GigaPoPs

As two versions of IP are used as bearer service for I2 network and support for direct ATM links is encouraged routing has to be done according to any of these. When QoS based routing in traffic inter-domain traffic is possible, it requires routing consideration.

Whenever it comes to IPv4, I2 project strongly recommends not to route anything from commercial Internet to any other gigapop. That is, only traffic originating or terminating to gigapop's members may be routed to public Internet. This decision is made in order to avoid congestions of public Internet. For IPv4 BGP (Border Gateway Protocol) and IDRP (Inter Domain Routing Protocol) are to be supported as well OSPF (Open Shortest-Path First Interior Gateway Protocol) eventhough there is no QoS support in them. Integrated Public Network-to-Network interface (I-PNNI) is one possibility for QoS based routing protocol for both IP versions as well as for ATM.

For IPv6 routing I-PNNI, IDRP, OSPF, RIPv6 (Routing Information Protocol) or BGP4++ (Border Gateway Protocol) may be used [3]. Routing on the ATM layer will also be needed, since QoS-related functions may need dynamic resource allocation which is done at the ATM layer. Both PVCs and SVC will be used, though the use of SVCs will be prefererable for example to avoid effects of network problems. Most of the ATM products have QoS support, but no policy filtering. However, since the amount of sites working with direct ATM is and will likely to remain small, the use of PNNI will suffice for the near future. 

3.2.4 Gigapop example

FloridaNet gigapop consists of one Cisco Lightstream 1010 ATM switch which serves those who need direct ATM connections. For IPv4, Cisco 7507 Router is used. Router supports also IGMP and RSVP [5]. To satisfy the needs for remote out-of-band access and performance data collection additional equiment is needed. For intra-gigapop routing, BGP4 is used and upgrades to its successors are done whenever required. Routing policy is implemented with a pair of route servers. Virtual paths (VP) are used between each DGP edge site and the ATM switch. Inside the VPs, virtual circuits are established to provide direct path from each edge site to every other and to core router. Network operation center (NOC) services are supplied by the University of Florida. Monitoring data is captured via RMON, NETFLOW, SNMP and OC3MON. This allows the studying of the traffic profiles in both normal and problem cases.

3.3 I2 Connectivity Cloud

• Very high reliability
• High capacity (bandwidth)
• Support for selectable QoS
• data-collection and circuit management tools for administrators

In addition to vBNS inter-gigapop linkage to other national network clouds is possible. This would allow experiments in multi-QoS network of multiple network providers after QoS problems between single network vendor gigapop-gigapop traffic have been solved. Multi-QoS traffic in a multi vendor network is likely to introduce new questions in e.g. accounting.

3.4 Local Networks

Generally, every campus will establish a high capacity circuit to the nearest gigapop and select an advanced functionality router as the campus gateway. If an experimental service testbed is required, campuses might also install an ATM multiplexer or switch between the campus and the gigapop. It is also assumed that campus-to-gigapop connection will carry non-I2 traffic, which is directed to separate link at the gigapop. During 1998 it is assumed that every campus connecting to a gigapop will establish at least a limited I2 capable network segment which allows testing and experimenting of I2 applications. By 2000 it is assumed that nearly every campus backbone is I2 connected [3], even though not every workstation will support I2 and some of the QoS questions may remain unsolved. Gradual transfer requires careful planning and management at the campus level.

3.4.1 Example: upgrade at University of Central Florida

In order to allow testing of I2 applications, an additional research ATM layer has been added to the production backbone. This is possible since as a result of rewiring project multiple category 5 cables are available to each desktop and fiber optic cables are installed to connect the wiring closets. Both single-mode and multi-mode fiber are installed.

4. I2 Network Services

4.1 Quality of service

• Transmission speed
• The minimum data rate and optionally target average and tolerable maximum data rates. As an example, an application might request connection data rate of which never falls below 50Mbps.
• Bounded delay and delay variance
• For real-time signals such as video only some limited interruptions are allowed. An application might request a connection that the gap between successive packets is 0.4s at maximum.
• Throughput
• The amount of data transmitted in given time period.
• Schedule
• Starting and ending times for service requested.
• Loss rate
• The maximum packet loss rate tolerated within a given time interval

4.2 Multicast

4.3 Measurement and optimization

• The cost for a service should be predictable
• Higher level of service should cost more than lower
• Resources consumed for accounting should be minimized and therefore accounting methods should be simple

4.4 Network management

4.5 Security

• Network system attacks
• A malicious person takes actions with a clear intent to degrade services provided by the network or cause intentional failures in the network. These attacks result in denial of service from the authorized users and they can take place in the form of flooding the network, spoofing network control protocols or illegally accessing network management systems.
• Unauthorized use of network
• Since different levels of service are provided, different resource controls and fees are associated with a level. Network must use authentication and authorization for obtaining services. Also mechanisms providing authentication and authorization services have to be immune to attacks.
• Inappropriate use of network
• This category covers actions that do not harm the network itself but the objects available via networks. These are mostly information systems and breaking into them is also considered under this category.

4.6 Network storage

5. I2 Applications

The main focus in the I2 project is to facilitate building applications which can be used for research and educational purposes. Therefore, investments done on applications can only be realized after I2 network infrastructure has spread to all universities, schools, workplaces and of course homes.

5.1 Application architecture concepts

5.1.1 Technical requirements for I2 applications

• Open APIs and services should be used
• Best practices are promoted to become standard rather than waiting for slow standardization procedures.
• Stateful network environment must be assumed by application developers.
• Applications must be written to be bandwidth-aware
• For example, different CODECs can be used depending on the network.
• Quality of service properties of I2 network infrastructure should be exploited

5.1.2 Important architectural concepts

With the middleware concept multi-tiered applications can separate data, process and presentation functions [8]. Middleware concept also allows developing APIs and toolkits that release applications developers from thinking about the networked environment. Therefore at least details of network performance and latency as well QoS details should be implemented as part of the middleware toolkit or as operating system functionality. Server side models of I2 application include multi-tiered servers where one client side application can use multiple servers for different functionality.

As a whole I2 application architecture makes use of the following concepts: [8]

• Components
• Objects, modules and possibly other forms of separate, but interworking software entities
• General purpose component classes
• Providing means for authentication, authorization and validation services as well as directory and presentation services
• Brokerage services
• Services for component, object and informations service location
• Run-time requesting and binding service which allows components and objects to construct fully operable applications
• Application programming interfaces
• Standardization of general purpose application support and service operations
• Information resource metadata services
• High level directory concept allowing application to locate the needed information resources
• Network service negotiation capabilities
• Services allowing applications to negotiate the network related resources like required bandwidth, QoS and latency levels
• Integrated network-wide applications performance, costing and utilization metrics
• Services allowing utilization metrics such as testing, tracing costing and performance measurement

5.2 Application types

5.2.1 Learningware

Instructional Management System (IMS) is a term for learningware concept which takes into account the learning process and provides both standards and services for incorporating multimedia rich instructional material and learning. The I2 project follows EDUCOM's National Learning Infrastructure Initiative which will create the standards for IMS on the Internet and I2. IMS standards will define data elements that belong to IMS applications. These include learning styles, learning modules and such. [9] .

An example of I2 learningware application includes remote jam sessions of music students and music teachers over high speed network connections [9].

5.2.2 Digital Libraries

While current Internet is sufficient for certain types of digital libraries multimedia libraries require more bandwidth and reliability than the current Internet can offer.

A related research activity on this area is data visualization and applying visualization analysis to non-textual data. This is also one of the focus areas of digital library applications.

5.2.3 Tele-immersion

5.2.4 Virtual Laboratory

• Computer servers for large scale simulations
• Databases containing research information
• Network connected scientific instruments
• Collaboration tools, maybe containing tele-immersion
• Software assets for simulation, data analysis, discovery and visualization

5.3 Application development schedule

5.4 Application Example: Provably Secure Videoconferencing

For this demonstration the desktop computer had switched 10Mb Ethernet connections to the campus edge system, which in turn was connected to a gigapop with 155Mb ATM connection. From the gigapop, 155Mb vBNS connection to other parties of the demonstration was available. The setup and network equipment used can be seen in Figure 5.1.

As an application platform IBM 42T RS6000 with integrated Ultimedia Services MJPEG was used. Hard coded encryption keys were used, though smartcard key exchange will also be possible [14]. A specific video snooper device was included to demonstrate third-party interception in unencrypted VIC session. Demonstration setup is illustrated in Figure 5.2.
 

6. Conclusions

Eventhough goals defined for the project are rather U.S. centric, it should be noted that the I2 project also aims at deployment of approved technologies and concepts in the global Internet. Also, since most of the corporate partners of the project will eventually manufacture the equipment for I2 organizations and they work in the global market, I2 technologies will spread across the public Internet. However, it is odd that no international co-operation is included in the I2 project agenda. This might cause resistance in Europe, at least if there are competing, local solutions available.

Gigapop is a concept introduced by I2. The benefit of the gigapop is to provide a single external connection point for different types of networks. This concept can simplify organizations' networks and make operations easier. It also enables smaller organisations to form a collective effort to share both costs and operation's workload. It can be assumed that the concept could be adopted by universities across the world. However, it is unlikely that companies would join their forces to form a shared gigapop. In the I2 model, the gigapop is operated by its members. This is also unlikely to happen in the commercial world, but the operation will be provided by the network operators. Still, the gigapop concept can be useful and it can to some extent be adopted by commercial network operators as a point of customer connection.

Establishing a gigapop requires investments. However, there are calculations showing that gigapop members can achieve significant economic benefits compared to situation where each of the gigapop members establishes an individual connection to the backbone network [15].

According to Gartner Group [16] , by 2001, 75% of the Internet services will be priced by usage. It is also known that even though there are lot of industrial partners participating the project paybacks will be made when concepts and equipment developed in the I2 project are extended to the commercial world. Most of the QoS issues are still in the drafting stages and it can be assumed that only after deployment of IPv6, QoS in IP-networks can be guaranteed on a level different than best effort. One interesting aspect of I2 infrastructure is ATM. ATM has been seen as complicated and expensive but offering better QoS support than other alternatives. The I2 project seems to have a great deal of faith in ATM and if it is found as a viable solution, the I2 project can give new boost for ATM-to-desktop visions.

Generally, the impact of I2 can be assumed to be notable. Most of the leading network equipment vendors of the current Internet are involved in I2 project. As soon as the project produces equipment or protocol specifications that can be commercially utilized, vendors will add these features to their products. Therefore, Gartner Group [16] recommends that organizations should rely on flat-rate pricing for some three years. During this period of time, network managers should start to measure and analyze current traffic to plan the budgets for the switching to usage-based pricing.

7. Glossary of Terms

BGP

CERT

Educom

MBONE

MUD

MOO

NSFnet

NGI, Next Generation Internet

UCAID

vBNS

References

[1] UCAiD, Internet2 Frequently Asked Questions <http://www.internet2.edu/html/faqs.html>

 

[2] UCAiD, Internet2 Project Mission & Goals <http://www.internet2.edu/html/mission_and_goals.html>

 

[3] UCAiD, Internet2 Preliminary Engineering Report, Chapter 3. Connectivity specifications and sources, Jan 1997, <http://www.internet2.edu/html/connectivity.html>

 

[4] UCAiD, Internet2 Preliminary Engineering Report, Chapter 2. Gigapops, Jan 1997, <http://www.internet2.edu/html/gigapops.html>

 

[5] FloridaNet, High Performance Connections Grant proposal, Aug 1997, <http://www.internet2.ufl.edu/prop/>

 

[6] Berger Peter, Quality of Service Administration issues, Nov 1997, <http://www.internet2.edu/presentations/QOS-SECU/sld001.htm>

 

[7] Mayer David, IP multicast issues, Nov 1997, <http://www.antc.uoregon.edu/I2/GO97/>

 

[8] UCAiD, Internet2 Applications working document, Architectural concepts, Jan 1997, <http://www.internet2.edu/html/architectural_concepts.html>

 

[9] UCAiD, Internet2 Applications working document, Application Examples: Learningware and Instructional management system, Jan 1997, <http://www.internet2.edu/html/learningware.html>

 

[10] UCAiD, Internet2 Applications working document, Application Examples: Digital Libraries and Information Access and Distribution, Jan 1997, <http://www.internet2.edu/html/digital_libraries.html>

 

[11] UCAiD, Internet2 Applications working document, The Virtual Laboratory: An Application Environment for Computational Science and Engineering, Jan 1997, <http://www.internet2.edu/html/virtual_laboratory.html>

 

[12] Hanss Ted, I2 applications priorities, May 1997 <http://www.internet2.edu/presentations/tedhanss_net97/>

 

[13] UCAiD, Internet2 application demonstration, Oct 1997, <http://www.internet2.edu/oct97/html/provably_secure_video-conferencing.html>

 

[14] University of Michigan, Internet2 application demonstrations, Oct 1997, <http://www.citi.umich.edu/projects/secure_video/Internet2_demo.html>

 

[15] vBNS, Gigapop FAQ, <http://www.vbns.net/Gigpop4.htm>

 

[16] GartnerGroup, Internet2 Is the First Step Toward Converged Data Networks Research Note, Jan 1998