A) Technical description of the investment
The investment aims to provide scientific institutions all over Poland with access to an innovative and secure network infrastructure and thus enable communication with scientific institutions all over the world via PIONIER (Polish Optical Internet) backbone network. Twenty Metropolitan Area Networks (MANs) will receive new network equipment in order to ensure and maintain the highest world standards in the scope of network infrastructure dedicated to scientific institutions connected with MANs all over Poland.
The present infrastructure of the MAN lacks coherence, which significantly hampers the realization of advanced teletransmission services for R&D and academic communities. In numerous cases the rendering of such a service must be preceded by a long-lasting and thorough analysis of the capabilities of all participants of a given project. That causes a considerable delay in implementing and launching new research projects. The internal infrastructures of many MANs are also not coherent. Various nodes of the MAN use different network technologies, which stems from the lack of funds that would enable building a modern and scalable teletransmission infrastructure.
The development of the network infrastructure will give more possibilities to connect subsequent scientific institutions to the local scientific MANs and enable the connected scientific institutions to use higher bandwidth links. Thanks to modern technologies, MANs and HPC centers will be much more reliable, and the network infrastructure will make it possible for scientific institutions connected with MANs to do research that requires access to the Internet and an opportunity to send information of the highest world parameters.
The Polish scientific community boasts one of the most innovative scientific networks called PONIER - Polish Optical Internet which uses two technologies: DWDM and Ethernet, offering its users multigigabit access. The current transmission capabilities of the network (20 Gb/s) enable to develop genuinely broadband services. However, their realization within MANs causes numerous problems.
Taking into account the world tendencies in the development of services rendered in broadband scientific networks, and following detailed analyses and discussions, the PIONIER Consortium Board has indicated the main directions of MAN development, including the following most significant elements:
o introducing the 1-Gigabit and 10-Gigabit Ethernet interfaces, and
o using the MPLS technology to realize advanced teletransmission services.
Adapting such technical and organizational solutions conforms with the world tendencies as well as parallel solutions developed by the pan-European Geant network.
B) Optimal technology
The innovative teleinformatic infrastructure includes the following data transmission services:
o voice transmission,
o data transmission,
o video transmission.
The implementation of innovative applications is conditioned by the development of a proper infrastructure of wide teleinformatic networks. Building a reliable and flexible teletransmission network is possible with the use of a vast array of technologies and network equipment.
Modern services require faster and faster connections that are available in the PIONIER and European networks. Consequently, the infrastructure of the MAN must provide transmission up 10 Gbit/s. Such tasks are difficult to realize in a network that is heterogeneous in terms of the transmission technology. The topologies of the designed networks must be damage-resistant and allow to be flexibly developed in the future. In the process of designing the extension of the MAN, measures were taken to protect it against overload that might hinder the network's efficiency. Moreover, the developers considered ensuring adequate capacity and efficiency of the network already at the planning stage.
Until recently the most common was the concept of building homogeneous networks in terms of teletransmission technologies and using equipment of one manufacturer. Such solutions may be optimized to meet thoroughly defined user needs and rendered services. Consequently, separate infrastructures were developed for data transmission (e.g. access to the Internet) or isochronic transmission (e.g. connecting switchboards). Such network are usually built as a result of a given project and further modifications. While it may be assumed that the applied solutions were properly chosen and implemented at the realization stage, such network infrastructure cannot be expected to meet new demands the new generation networks will have to face. The MANs must meet new requirements resulting from a sustained development of services and growing user demands.
The MANs are using a wide array of available teletransmission technologies such as ATM, SDH, Frame Relay and Ethernet. Though highly flexible, many of them did not manage to keep pace with the transmission speed, which led to migrating to the more affordable Ethernet. As they develop, however, the networks based exclusively on the Ethernet technology contend with a growing problem of scalability. The switching technology in the Layer 2 of the OSI model has been developed to link computer systems into Local Area Networks (LANs). As network interfaces were inexpensive, the scope of the networks was expanded. Uncontrollable development of LANs causes problems with their stability and reliability, because the Ethernet technology does not have steering and protective mechanisms that would be efficient enough.
It seriously impedes connecting networks of different institutions since the broadcast domain is excessively expanding. Moreover, ostensible simplicity of such mechanisms as spanning-tree (or its derivatives) does not mean that their operation would ensure network reliability. The mechanisms are frequently not able to take into account the impact of network topology on outlining optimal back-up paths. Errors in their functioning may also have disastrous consequences in terms of a given teleinformatic network as well as its co-operating networks. In case of improper work of the spanning-tree mechanisms, the Ethernet network may see a phenomenon of looping frames on some network links. Such loop causes disturbances both in the control plane and data plane. Disturbances in the control plane significantly hinder or even make it impossible to make a diagnosis and solve the problem, and in the data plane they result in losing the whole available band by engaging it with repeated sending of copies of the same frames. For this reason special attention should be paid to the parameters and scalability of the protective mechanisms.
In the process of designing the extension of the MAN it was assumed that the devices would be equipped with fast and inexpensive 1 Gigabit- and 10 Gigabit Ethernet interfaces, but switching would not be realized on the basis of the Layer 2 header. Building a reliable and flexible teleinformatic network of a metropolitan scope is feasible by means of several technologies:
o Routing IPv4(IPv6) and 3 layer VPN network
o Multiprotocol Label Switching - MPLS
The IP protocol is so commonly used that it is possible to build fast and efficient metropolitan networks. The possibility of realizing the VPN network substantially expands the functionality of the network by dedicating part of the resources to certain services. The IP protocol operates in layer 3 of the OSI model, hence it is possible to use various data link technologies, such as Ethernet, PoS, Frame Realy and ATM. A serious limitation of networks operating exclusively with the IP protocol is a significantly hampered possibility to emulate the services of the second layer OSI model. While the tunneling mechanisms are available, their compatibility and scalability are far from being satisfactory. Moreover, it is often impossible to outline exact routes along which the network traffic would be sent as there is a lack of advanced traffic engineering mechanisms.
Owing to the abovementioned limitations, a technology connecting advantages of packet switching with the independence of the technology used in the data link layer has been developed. This technology uses commutation on the basis of labels, i.e. Multiprotocol Label Switching (MPLS).
The architecture of this technology has been described in the standard RFC3031 "Multiprotocol Label Switching Architecture". The concept of marking packets by means of labels constituting the basis for switching has been introduced. Labels may create hierarchical structures thanks to using label piles. The MPLS technology is based on the Forwarding Equivalence Class, the key component causing its unusual flexibility. Packets may be classified according to a variety of criteria. After the classification the devices label a given class, and data is sent within the network on the bass of the labels. Label exchange is executed by means of dedicated protocols or existing extensions.
Thanks to introducing the FCE, the MPLS technology allows to emulate different types of services. One common network infrastructure allows to realize such services as:
o Layer 3 VPN networks
o Layer 2 VPN networks
o IPv4 and IPv6 packet transfer.
Until recently these services could be realized only in dedicated networks. Using MPLS networks significantly increases the scope of using the infrastructure to realize numerous and often diverse services.
It is thus possible to transfer ATM cells, Ethernet frames, etc. via the MPLS, notwithstanding the type of technology used by the interfaces of the backbone network nodes. It significantly facilitates fluent migration from the network of the former structure to a new one in the MPLS technology. Additionally, it is possible to use the MPLS network as a transmission medium for the needs of other networks.
Thanks to using such technologies as the VPLS, it is possible to emulate segments of the LAN in the MPLS network. The possibility of using closed VPN networks considerably increases the security level of data transferred via the network.
Fast and flexibly built VPN networks lead to more effective use of partners' resources within various R&D projects owing to their sharing and virtualization.
The MPLS technology also provides a range of advanced steering mechanisms that allow for the realization of the Traffic Engineering function as well as effective protection mechanisms. Traffic steering includes such functions as reservation of network resources to ensure proper QoS parameters as well as complex rules of outlining routes to transfer data. The mechanisms make it possible for network devices to dynamically react to faults and prevent overload. Thanks to the QoS mechanisms it is also possible to connect services generating traffic of different characteristics and requiring various quality parameters within the same network. The MPLS network allows for simultaneous sending of isochronous streams and data while retaining the quality of service for both.
The standardization of protocols required to build networks in the MPLS technology makes it possible to use equipment of various producers within the same network. Consequently, the costs of network development are lowered because products of numerous producers are available.
When the Ethernet technology is used only as a framing mechanism on an interface along with advanced MPLS steering protocols, it is feasible to build big and well scalable teleinformatic networks. The scalability of network solutions is important in the case of cooperation within the PIONIER Consortium, since it is possible to flexibly connect MANs with one another in order to realize broadband services.
It should be noted that an MPLS technology network may act as a flexible, reliable and effective transmission medium for building the backbone of the MAN. As MPLS in independent of the second layer OSI model technology (ATM, Ethernet, etc.) and the third layer protocols (IPv4, IPv6), it protects the investment for the future and prepares it for the introduction of innovative network technologies.
The MPLS technology has been successfully implemented in the Polish national R&D optical network named PIONIER. Consequently, it is necessary to achieve technological coherence between the MANs and the PIONIER network in order to realize advanced broadband services for R&D communities.
Thanks to the possibility of using the most modern transmission technologies, the Polish R&D and academic communities are getting more and more competitive for the European and world partners. Thus they may enjoy equal opportunities to participate in international research projects and lead their own projects on the highest level.
C) Defining needs and types of devices
Within the PIONIER Consortium research was done on the demand for network equipment allowing for the realization of broadband services in the MANs. The results showed that the development of the MAN infrastructures would have to include both the network backbone layer and the access layer. It is conditioned by the need to maintain technological coherence within the network using MPLS mechanisms.
For the needs of development works the architecture of backbone and access devices was defined. The availability of those devices on the market was analyzed and costs were estimated. The products available on the market were analyzed according to their architecture innovation, development perspectives of a given platform and the possibility of long-term use in the network. Particular attention was paid to whether the producers were prepared to install interfaces that might work at the speed of 100 Gbit/s and, in a dozen years' time, would be more and more extensively used in network backbones, as well as plans of the steering software.
The market research determined at least three leading producers of network equipment that would be able to provide the required devices. Their backbone equipment have been tested in the PSNC lab and are being used both in the PIONIET network and some MANs.
Owing to the choice of the MPLS technology, a switch denotes a device allowing to switch packets according to labels. In order to ensure coherent and fluent migration to the MPLS technology, it was assumed that backbone and access switches would have to come from one producer.
Details of the technical and functional parameters for the switches will be defined in the Specification of Essential Terms of Contract (SIWZ) taking into account the current state of technological advent in reference to the devices available on the market.
The access switch must be equipped with interfaces enabling to connect users in the Ethernet technology at the speed up to 1Gbps, as well as at least two 10GigabitEthernet interfaces to connect to the network backbone. As there are many devices of this type and it is necessary to reduce the investment costs, it was assumed that they would not have to be the modular switches.
The switch must have the functionality of an MPLS network access device, which means that it must allow to classify and mark traffic with a proper label(s). The switches are required to offer line-rate switching. The architecture of the tool must allow for lossless data exchange between any interfaces, notwithstanding the band occupied by a single data stream. On account of the MAN topology it should be possible to join access switches into a chain to be connected to the network backbone in two points.
The backbone switch must be a tool of modular architecture, equipped with at least five 10GigabitEthernet interfaces to interconnect backbone devices and access switches. Additionally, the switch must be equipped with Gigabit Ethernet switches (optical or UTP) to enable connecting users located in the backbone node. It must also make it possible to add subsequent 10GigabitEthernet interfaces.
The switches are required to offer line-rate switching. The architecture of the tool must allow for lossless data exchange between any interfaces placed on different line cards, notwithstanding the band occupied by a single data stream.
The line cards of the switch containing 10GE interfaces must cooperate with XFP modules compliant with the 802.3ae norm and purchased from various producers. The10GE interfaces must provide a choice of work mode: LAN PHY or WAN PHY.
Proper management of the following MPLS services is required for all line interfaces of the switch:
o VLL (Virtual Leased Lines),
o VPLS (Virtual Private LAN Services),
o BGP/MPLS VPN (RFC 2547)
The switch must operate the Connectivity Fault Management for the VPLS instance compliant with the IEEE 802.1ag standard. The MPLS OAM functionality that allows for checking the LSP ping and its traceroute must also be available. These functions must be available for both the pings linked by means of the LDP and RSVP protocols.
The switch must operate jumbo frames of at least 9216B as well as IP multicast.