Pub Date : 2007-06-10DOI: 10.1109/LANMAN.2007.4295977
M. Wadekar
Data Centers today deploy multiple fabrics for LAN, SAN and IPC traffic. This introduces significant cost, complexity and management challenges. Hence there is strong demand for consolidating these multiple fabrics. Ethernet is default fabric used primarily for LAN traffic and it is low-cost, well-known, widely available, and broadly compatible. So, it makes an ideal candidate for such IO consolidation. However, current Ethernet suffers from certain deficiencies that need to be addressed. Legacy Ethernet suffers from 3 main issues (a) Lack of congestion management mechanism -which results in packet drops when network is congested. This also results in unpredictable latencies for the traffic through these congested networks, (b) No standard mechanism for traffic differentiation on the link which will protect all the traffic types on consolidated link. Only mechanism available is 802. lp strict prioritization without any bandwidth assurance, (c) Poor utilization of available bandwidth in the network. Spanning Tree Protocol tends to remove links that can cause loops in the network. This results in lower bisectional bandwidth. Underlying Layer 2 protocols do not allow any multipathing techniques that are available in other technologies like Fiber Channel, Infiniband etc. This paper presents a framework of solution that includes multiple enhancements to Ethernet network -that will improve legacy Ethernet significantly for Data Center deployment. Some of these enhancements are being pursued in IEEE and IETF for standardization. IEEE 802.1Qau Task Force is focusing on improving congestion management capabilities of Ethernet IEEE 802.1Qat and IETF-TRILL is focusing on improving bisectional bandwidth by allowing L2 multipathing capabilities for complex and large DC deployments. Other efforts include mechanisms for better traffic differentiation and improved link level flow control for data center -Ethernet. This paper will elaborate more on congestion management related work.
{"title":"Enhanced Ethernet for Data Center: Reliable, Channelized and Robust","authors":"M. Wadekar","doi":"10.1109/LANMAN.2007.4295977","DOIUrl":"https://doi.org/10.1109/LANMAN.2007.4295977","url":null,"abstract":"Data Centers today deploy multiple fabrics for LAN, SAN and IPC traffic. This introduces significant cost, complexity and management challenges. Hence there is strong demand for consolidating these multiple fabrics. Ethernet is default fabric used primarily for LAN traffic and it is low-cost, well-known, widely available, and broadly compatible. So, it makes an ideal candidate for such IO consolidation. However, current Ethernet suffers from certain deficiencies that need to be addressed. Legacy Ethernet suffers from 3 main issues (a) Lack of congestion management mechanism -which results in packet drops when network is congested. This also results in unpredictable latencies for the traffic through these congested networks, (b) No standard mechanism for traffic differentiation on the link which will protect all the traffic types on consolidated link. Only mechanism available is 802. lp strict prioritization without any bandwidth assurance, (c) Poor utilization of available bandwidth in the network. Spanning Tree Protocol tends to remove links that can cause loops in the network. This results in lower bisectional bandwidth. Underlying Layer 2 protocols do not allow any multipathing techniques that are available in other technologies like Fiber Channel, Infiniband etc. This paper presents a framework of solution that includes multiple enhancements to Ethernet network -that will improve legacy Ethernet significantly for Data Center deployment. Some of these enhancements are being pursued in IEEE and IETF for standardization. IEEE 802.1Qau Task Force is focusing on improving congestion management capabilities of Ethernet IEEE 802.1Qat and IETF-TRILL is focusing on improving bisectional bandwidth by allowing L2 multipathing capabilities for complex and large DC deployments. Other efforts include mechanisms for better traffic differentiation and improved link level flow control for data center -Ethernet. This paper will elaborate more on congestion management related work.","PeriodicalId":347028,"journal":{"name":"2007 15th IEEE Workshop on Local & Metropolitan Area Networks","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131181788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-06-10DOI: 10.1109/LANMAN.2007.4295990
Abhijit A. Bare, A. Jayasumana, N. Piratla
The network link speeds increase at a higher rate compared to processing speeds. This coupled with the increase in size of router tables demand higher levels of parallelism within router hardware. However, such parallelism introduces unintended consequences that potentially may negate some of the performance gains provided by the improved technology. The growth trends of computing speeds, link speeds, and routing table sizes are used to evaluate one such consequence, packet reordering within routers. Results presented show the trends related to the degree of hardware parallelism and packet reordering.
{"title":"On Growth of Parallelism within Routers and Its Impact on Packet Reordering","authors":"Abhijit A. Bare, A. Jayasumana, N. Piratla","doi":"10.1109/LANMAN.2007.4295990","DOIUrl":"https://doi.org/10.1109/LANMAN.2007.4295990","url":null,"abstract":"The network link speeds increase at a higher rate compared to processing speeds. This coupled with the increase in size of router tables demand higher levels of parallelism within router hardware. However, such parallelism introduces unintended consequences that potentially may negate some of the performance gains provided by the improved technology. The growth trends of computing speeds, link speeds, and routing table sizes are used to evaluate one such consequence, packet reordering within routers. Results presented show the trends related to the degree of hardware parallelism and packet reordering.","PeriodicalId":347028,"journal":{"name":"2007 15th IEEE Workshop on Local & Metropolitan Area Networks","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114570413","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-06-10DOI: 10.1109/LANMAN.2007.4295981
T. Truong, M. Baldi, Y. Ofek
Time-driven Switching (TDS) networks with non-immediate forwarding (NIF) provides scheduling flexibility and consequently, reduces the blocking probability (blocking is defined to take place when transmission capacity is available, but without a feasible schedule). However, it has been shown that with NIF scheduling complexity may grow exponentially. Efficiently finding a schedule from an exponential set of potential schedules is the focus of this paper. The work first presents the mathematical formulation of the NIF scheduling problem, under a wide variety of networking requirements, then introduces an efficient (i.e., having at most polynomial complexity) search algorithm that guarantees to find at least one schedule whenever such a schedule exists. The novel algorithm uses 'trellis' representations and the well-known survivor-based searching principle.
{"title":"An Efficient Scheduling Algorithm for Time-Driven Switching Networks","authors":"T. Truong, M. Baldi, Y. Ofek","doi":"10.1109/LANMAN.2007.4295981","DOIUrl":"https://doi.org/10.1109/LANMAN.2007.4295981","url":null,"abstract":"Time-driven Switching (TDS) networks with non-immediate forwarding (NIF) provides scheduling flexibility and consequently, reduces the blocking probability (blocking is defined to take place when transmission capacity is available, but without a feasible schedule). However, it has been shown that with NIF scheduling complexity may grow exponentially. Efficiently finding a schedule from an exponential set of potential schedules is the focus of this paper. The work first presents the mathematical formulation of the NIF scheduling problem, under a wide variety of networking requirements, then introduces an efficient (i.e., having at most polynomial complexity) search algorithm that guarantees to find at least one schedule whenever such a schedule exists. The novel algorithm uses 'trellis' representations and the well-known survivor-based searching principle.","PeriodicalId":347028,"journal":{"name":"2007 15th IEEE Workshop on Local & Metropolitan Area Networks","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124971359","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-06-10DOI: 10.1109/LANMAN.2007.4295986
Jing Chen, Minjian Zhao, Shiju Li
Making efficient use of network resources is of great importance in wireless networks. In this paper, we propose a cross-layer algorithm to minimize the energy consumption and provide QoS guarantee jointly for various connections with different QoS requirements in wireless cellular networks. We formulate an admission control problem and a multiple objective programming problem which allocates the rate and network resource for each connection in the network simultaneously. We derive efficient solutions to the two problems which attain an efficient usage of the transmission powers, and guarantee the rate and delay requirements of every admitted connection in the network. The simulation results show that our algorithm makes use of the network resource more effectively than layered approaches and our algorithm can be implemented in various wireless cellular networks with fast convergence.
{"title":"Connection-based Cross-layer Design in Wireless Cellular Networks","authors":"Jing Chen, Minjian Zhao, Shiju Li","doi":"10.1109/LANMAN.2007.4295986","DOIUrl":"https://doi.org/10.1109/LANMAN.2007.4295986","url":null,"abstract":"Making efficient use of network resources is of great importance in wireless networks. In this paper, we propose a cross-layer algorithm to minimize the energy consumption and provide QoS guarantee jointly for various connections with different QoS requirements in wireless cellular networks. We formulate an admission control problem and a multiple objective programming problem which allocates the rate and network resource for each connection in the network simultaneously. We derive efficient solutions to the two problems which attain an efficient usage of the transmission powers, and guarantee the rate and delay requirements of every admitted connection in the network. The simulation results show that our algorithm makes use of the network resource more effectively than layered approaches and our algorithm can be implemented in various wireless cellular networks with fast convergence.","PeriodicalId":347028,"journal":{"name":"2007 15th IEEE Workshop on Local & Metropolitan Area Networks","volume":"79 4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132755713","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-06-10DOI: 10.1109/LANMAN.2007.4295994
K. Imran, M. Mellia, M. Meo
In this paper, we present measurement results collected from real traces on the network FastWeb, an ISP provider that is the main broadband telecommunication company in Italy. The network relies on a fully IP architecture and delivers to the user services such as data, VoIP and IP television over a single broadband connection. Our measurements, that are based on a passive measurement technique, focus on IP Television (IPTV) multicast, that consists of 83 digital TV channels encoded using different MPEG-2 encoders. The results show that, depending on the encoder and based on the bitrate, flows can be classified as being: CBR, 2-VBR (i.e., two typical bitrate values) and VBR. Measurement of the packet loss, jitter and inter-packet gap show that, independently from the class, packet generation process of the flows can have various degrees of burstiness. Despite the packet level burstiness, average jitter is limited to few milliseconds and no packet loss was ever observed, showing that the quality of IPTV offered by FastWeb is excellent.
{"title":"Measurements of Multicast Television over IP","authors":"K. Imran, M. Mellia, M. Meo","doi":"10.1109/LANMAN.2007.4295994","DOIUrl":"https://doi.org/10.1109/LANMAN.2007.4295994","url":null,"abstract":"In this paper, we present measurement results collected from real traces on the network FastWeb, an ISP provider that is the main broadband telecommunication company in Italy. The network relies on a fully IP architecture and delivers to the user services such as data, VoIP and IP television over a single broadband connection. Our measurements, that are based on a passive measurement technique, focus on IP Television (IPTV) multicast, that consists of 83 digital TV channels encoded using different MPEG-2 encoders. The results show that, depending on the encoder and based on the bitrate, flows can be classified as being: CBR, 2-VBR (i.e., two typical bitrate values) and VBR. Measurement of the packet loss, jitter and inter-packet gap show that, independently from the class, packet generation process of the flows can have various degrees of burstiness. Despite the packet level burstiness, average jitter is limited to few milliseconds and no packet loss was ever observed, showing that the quality of IPTV offered by FastWeb is excellent.","PeriodicalId":347028,"journal":{"name":"2007 15th IEEE Workshop on Local & Metropolitan Area Networks","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114255307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-06-10DOI: 10.1109/LANMAN.2007.4295979
Paul Stoian, I. Cidon
MANs and backbone networks are shared by "users" that can be individuals, organizations as well as communication service providers. Such users produce concurrently a variety of traffic patterns from multiple network locations. Traditional fairness definitions allocate bandwidth to individual source to destination flows. These individual flow fairness definitions generally allocate more bandwidth to users with a larger number of flows, thus creating unfairness at the user level. This paper explores alternative user level fairness criteria. We examine several extensions of the max-min fairness that allocate bandwidth fairly to users. We require the new criteria to be based on a max-min definition, to be backward compatible with the traditional max-min fairness (when each user has a single flow) and not to allocate zero bandwidth to any individual flow. We describe three different criteria for fair bandwidth allocation to users. The first is a weighted max-min criteria, achieving user fairness by the weights assigned to each flow; The second attempts to balance the user allocation separately over each link; Finally, we introduce a novel scheme termed the redefined vector-space fairness that is based on a lexicographical maximization of both user and individual flows. This paper evaluates the three fairness definitions both behaviorally and numerically. The simulation results show a clear advantage for the redefined vector-space fairness both in terms of user fairness and overall throughput.
{"title":"Aggregate Flow Fairness in MANs","authors":"Paul Stoian, I. Cidon","doi":"10.1109/LANMAN.2007.4295979","DOIUrl":"https://doi.org/10.1109/LANMAN.2007.4295979","url":null,"abstract":"MANs and backbone networks are shared by \"users\" that can be individuals, organizations as well as communication service providers. Such users produce concurrently a variety of traffic patterns from multiple network locations. Traditional fairness definitions allocate bandwidth to individual source to destination flows. These individual flow fairness definitions generally allocate more bandwidth to users with a larger number of flows, thus creating unfairness at the user level. This paper explores alternative user level fairness criteria. We examine several extensions of the max-min fairness that allocate bandwidth fairly to users. We require the new criteria to be based on a max-min definition, to be backward compatible with the traditional max-min fairness (when each user has a single flow) and not to allocate zero bandwidth to any individual flow. We describe three different criteria for fair bandwidth allocation to users. The first is a weighted max-min criteria, achieving user fairness by the weights assigned to each flow; The second attempts to balance the user allocation separately over each link; Finally, we introduce a novel scheme termed the redefined vector-space fairness that is based on a lexicographical maximization of both user and individual flows. This paper evaluates the three fairness definitions both behaviorally and numerically. The simulation results show a clear advantage for the redefined vector-space fairness both in terms of user fairness and overall throughput.","PeriodicalId":347028,"journal":{"name":"2007 15th IEEE Workshop on Local & Metropolitan Area Networks","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123711977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-06-10DOI: 10.1109/LANMAN.2007.4295966
Jian Zhang, Y. Chen, I. Marsic
Wireless mesh networks are flexible solutions to extend services from wireless LANs. The current IEEE 802.11 Specification, however, needs to be modified in various ways to be a suitable technology for this purpose. In particular, in order to handle the well-known hidden node problem (HNP), the Specification adopts MACAW by employing an RTS/CTS/DATA/ACK 4-way handshake. Some flaws of this scheme have been noticed, e.g. the Masked Node Problem (MNP). In this work, we identify a critical problem of the Specification's 4-way handshake, called persistent pseudo-clearance (PPC). PPC occurs when for two sender/receiver pairs a CTS from one pair's receiver collides with the DATA frames of the other pair. This logjam can persist for a period of time despite of the random backoff the senders employ. The persistent frame losses in PPC can cause more serious problems. The effect of giving up a frame transfer after reaching the maximum number of retries can propagate to upper layers, causing routing errors or TCP sender backoff. Multicast RTS (or MRTS) provides a good solution framework to break the cycle of losses and retransmissions between such peers. With minimal modification to MRTS, we provide an effective and efficient solution to PPC. Our experiments show that MRTS breaks the logjam of PPC while fully utilizing the network capacity.
{"title":"Persistent Pseudo-Clearance Problem in IEEE802.11 Mesh Networks and its Multicast Based Solutions","authors":"Jian Zhang, Y. Chen, I. Marsic","doi":"10.1109/LANMAN.2007.4295966","DOIUrl":"https://doi.org/10.1109/LANMAN.2007.4295966","url":null,"abstract":"Wireless mesh networks are flexible solutions to extend services from wireless LANs. The current IEEE 802.11 Specification, however, needs to be modified in various ways to be a suitable technology for this purpose. In particular, in order to handle the well-known hidden node problem (HNP), the Specification adopts MACAW by employing an RTS/CTS/DATA/ACK 4-way handshake. Some flaws of this scheme have been noticed, e.g. the Masked Node Problem (MNP). In this work, we identify a critical problem of the Specification's 4-way handshake, called persistent pseudo-clearance (PPC). PPC occurs when for two sender/receiver pairs a CTS from one pair's receiver collides with the DATA frames of the other pair. This logjam can persist for a period of time despite of the random backoff the senders employ. The persistent frame losses in PPC can cause more serious problems. The effect of giving up a frame transfer after reaching the maximum number of retries can propagate to upper layers, causing routing errors or TCP sender backoff. Multicast RTS (or MRTS) provides a good solution framework to break the cycle of losses and retransmissions between such peers. With minimal modification to MRTS, we provide an effective and efficient solution to PPC. Our experiments show that MRTS breaks the logjam of PPC while fully utilizing the network capacity.","PeriodicalId":347028,"journal":{"name":"2007 15th IEEE Workshop on Local & Metropolitan Area Networks","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121901870","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-06-10DOI: 10.1109/LANMAN.2007.4295993
Changhoon Kim, J. Rexford
Because Ethernet bridging does not scale, most enterprise networks consist of small Ethernet-based subnets interconnected by IP routers. Although Ethernet's flat addressing and transparent bridging allow each subnet to run with minimal configuration, interconnecting subnets at the IP level introduces significant management overhead that increases with the size of the network. As an alternative, we propose a scalable and efficient zero-configuration enterprise (SEIZE) networking architecture. SEIZE provides plug-and-play capability via globally unique flat addressing, while ensuring scalability and efficiency through shortest-path routing and hash-based location resolution. Switches perform location resolution on demand and can cache the results to optimize routing paths and to reduce the number of location-resolution requests. We present a design overview of SEIZE and show that it attains the best of Ethernet and IP.
{"title":"Revisiting Ethernet: Plug-and-play made scalable and efficient","authors":"Changhoon Kim, J. Rexford","doi":"10.1109/LANMAN.2007.4295993","DOIUrl":"https://doi.org/10.1109/LANMAN.2007.4295993","url":null,"abstract":"Because Ethernet bridging does not scale, most enterprise networks consist of small Ethernet-based subnets interconnected by IP routers. Although Ethernet's flat addressing and transparent bridging allow each subnet to run with minimal configuration, interconnecting subnets at the IP level introduces significant management overhead that increases with the size of the network. As an alternative, we propose a scalable and efficient zero-configuration enterprise (SEIZE) networking architecture. SEIZE provides plug-and-play capability via globally unique flat addressing, while ensuring scalability and efficiency through shortest-path routing and hash-based location resolution. Switches perform location resolution on demand and can cache the results to optimize routing paths and to reduce the number of location-resolution requests. We present a design overview of SEIZE and show that it attains the best of Ethernet and IP.","PeriodicalId":347028,"journal":{"name":"2007 15th IEEE Workshop on Local & Metropolitan Area Networks","volume":"175 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114343276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-06-10DOI: 10.1109/LANMAN.2007.4295973
J. Akella, M. Yuksel, S. Kalyanaraman
Free-Space Optical communication technology is a potential solution to the last mile or broadband access problem. Conventional free-space optical (FSO) communication is over a single link between two nodes. We explore multi-channel FSO communication system using compact (a maximum of a Sq.Ft) 2-dimensional antennas with multiple communication links between them to achieve very high aggregate bandwidths (100's of Gbps). But, close packaging of optical channels on the arrays causes inter-channel interference, reducing per channel capacity. We model the error due to inter-channel interference for such arrays and estimate the channel capacity. We address the multi-channel interference issue by both array design and by employing optical orthogonal codes (OOCs) for free-space optical communications and show that we can achieve multi Gbps bandwidths using such arrays. Possible applications for such multi-channel FSO systems can be in multi-hop broadband access networks or mesh networks and in back haul, connecting wireless base stations.
{"title":"Multi-channel Communication in Free-Space Optical Networks for the Last-mile","authors":"J. Akella, M. Yuksel, S. Kalyanaraman","doi":"10.1109/LANMAN.2007.4295973","DOIUrl":"https://doi.org/10.1109/LANMAN.2007.4295973","url":null,"abstract":"Free-Space Optical communication technology is a potential solution to the last mile or broadband access problem. Conventional free-space optical (FSO) communication is over a single link between two nodes. We explore multi-channel FSO communication system using compact (a maximum of a Sq.Ft) 2-dimensional antennas with multiple communication links between them to achieve very high aggregate bandwidths (100's of Gbps). But, close packaging of optical channels on the arrays causes inter-channel interference, reducing per channel capacity. We model the error due to inter-channel interference for such arrays and estimate the channel capacity. We address the multi-channel interference issue by both array design and by employing optical orthogonal codes (OOCs) for free-space optical communications and show that we can achieve multi Gbps bandwidths using such arrays. Possible applications for such multi-channel FSO systems can be in multi-hop broadband access networks or mesh networks and in back haul, connecting wireless base stations.","PeriodicalId":347028,"journal":{"name":"2007 15th IEEE Workshop on Local & Metropolitan Area Networks","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134312316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-06-10DOI: 10.1109/LANMAN.2007.4295980
W. Colitti, K. Steenhaut, A. Nowé
Due to the unpredictability of IP traffic, MANs are migrating from SONET/SDH ring architectures to DWDM mesh infrastructures. Firstly, the fast advance in optical technologies has provided DWDM networks with extremely high bandwidth capability (i.e. OC-192 and OC-768). Secondly, Generalized Multi Protocol Label Switching (GMPLS) and Multilayer Traffic Engineering (MTE) paradigms have turned them into highly flexible, scalable and cost efficient infrastructures able to improve service provider's return on investment (ROI). With the GMPLS automated control plane, IP/DWDM networks can take advantage of a better integration between the electrical and optical domains and consequently of a more optimized resource usage. GMPLS enables network-state-depended dynamic routing and grooming and provides network operators with the tools to differentiate service types and increase the offered QoS. This paper discusses the benefits of GMPLS as an integrator paradigm in IP/DWDM metro infrastructures and proposes a QoS control framework which allows a network operator to accommodate MPLS/DiffServ traffic on different virtual topologies that can guarantee different QoS levels. The benefits of GMPLS/MTE and of the proposed scheme are discussed by means of simulation results.
{"title":"QoS in GMPLS based IP/DWDM Metro Networks","authors":"W. Colitti, K. Steenhaut, A. Nowé","doi":"10.1109/LANMAN.2007.4295980","DOIUrl":"https://doi.org/10.1109/LANMAN.2007.4295980","url":null,"abstract":"Due to the unpredictability of IP traffic, MANs are migrating from SONET/SDH ring architectures to DWDM mesh infrastructures. Firstly, the fast advance in optical technologies has provided DWDM networks with extremely high bandwidth capability (i.e. OC-192 and OC-768). Secondly, Generalized Multi Protocol Label Switching (GMPLS) and Multilayer Traffic Engineering (MTE) paradigms have turned them into highly flexible, scalable and cost efficient infrastructures able to improve service provider's return on investment (ROI). With the GMPLS automated control plane, IP/DWDM networks can take advantage of a better integration between the electrical and optical domains and consequently of a more optimized resource usage. GMPLS enables network-state-depended dynamic routing and grooming and provides network operators with the tools to differentiate service types and increase the offered QoS. This paper discusses the benefits of GMPLS as an integrator paradigm in IP/DWDM metro infrastructures and proposes a QoS control framework which allows a network operator to accommodate MPLS/DiffServ traffic on different virtual topologies that can guarantee different QoS levels. The benefits of GMPLS/MTE and of the proposed scheme are discussed by means of simulation results.","PeriodicalId":347028,"journal":{"name":"2007 15th IEEE Workshop on Local & Metropolitan Area Networks","volume":"255 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115777485","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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