E.L. Nygren, S.J. Garland, M.F. Kaashoek, PAN: a high-performance active network node supporting multiple mobile code system, Proceedings of the Second IEEE Conference on Open Architectures and Network Programming (OpenArch'99) March (1999).  Home/Search   Document Details and Download   Summary   Related Articles   Check

....of packet forwarding. The application of capsules to packet forwarding is a question of what the ratio of computational resources is to the possible packet rate and bandwidth. The prototype systems discussed here are already suitable for links in the tens of Mbps range, while more advanced systems [23], 18] perform similarly to other software based routers running on general purpose hardware, where hundreds of Mbps can be supported. Since capsules can provide sophisticated firewall capabilities, it is important to note that these results suggest that current firewalls could be made active ....

E. Nygren, S. Garland, and M. F. Kaashoek, "PAN: A high-performance active network node supporting multiple mobile code systems," in Proceedings of the 1999.

.... such a remote invocation is semantically (and functionally) equivalent to sending a packet. A PLAN capsule contains a chunk, which represents a delayed remote PLAN evaluation. See Section 2.2.2 for more details on PLAN chunks. The Active Node Transfer System (ANTS) Wetherall98] and PAN [Nygren99] from MIT support demand loading and caching of code at a network node. Each active capsule is tagged with a code identifier. The code identifier is implemented as a secure hash (such as MD5 [Rivest92] or SHA 1 [NIST95] of the Java [Gosling95b] class (ANTS) or generic code object (PAN) that ....

....Click router toolkit [Morris99] have been proposed to support a similar but lower level functionality in an extensible router, with modules implemented for various functions that a router may be required to perform, and connections set up between modules and the underlying platform. PAN [Nygren99] supports an active network implementation running unsafe native code entirely within a Linux kernel loadable module; it aims to perform zero copy active routing for those packets that are simply being custom routed and forwarded to their ultimate destinations. Other projects have recognised that ....

[Article contains additional citation context not shown here]

Erik L. Nygren, Stephen J. Garland, and M. Frans Kaashoek. PAN: A High-Performance Active Network Node Supporting Multiple Mobile Code Systems. In Proceeding of the 2nd IEEE Conference on Open Architectures and Network Programming (OPENARCH '99), pages 78--89, March

....solutions are shown below. Reference approach: ANEP Protocol[24] uses Protocol Identifier field in IP header to identify ANEP packet. The ANEP is a protocol designed for APN support. It includes a Type ID field to demultiplex between different EEs (different APN architecture) Nygren et al. [25] and Wetherall et al. 26] use a similar approach which uses some header to identifier the EE. Tag approach: Simple Active Packet Forwarding (SAPF) 27] intro duces a shim layer on top of the link layer. A tag is injected at the front of the packet to demultiplex between EEs. The tag becomes a ....

E. Nygren, S. Garland, , and M. Kaashoek, "PAN: A high-performance active network node supporting multiple mobile code systems," IEEE Communications, pp. 78-89, 1999.

....of user code within a virtual machine (like Java) provides a high degree safety of execution, it also has associated performance costs. This is the timehonored approach of relying on the code supplier for safety in order to obtain better performance. The aim of Practical Active Network (PAN) [22] project is also to build a high performance capsule based active node that is based on the ANTS framework. Architecturally, PAN is an in kernel implementation of an EE using Linux as the node OS, able to saturate a 100 Mbps Ethernet with 1500 byte capsules containing native code and executed ....

NYGREN, E., et al., "PAN: A High-Performance Active Network Node Supporting Multiple Mobile Code Systems," IEEE OpenArch '99, March 1999.

....resources at a sufficiently low level, any development using ANTS on standard platforms can support only modest quality ofservice capabilities, and are limited to the basic network capabilities provided by Java. High performance can also be obtainable using recent amelioration to ANTS [10]. 7. Conclusions Viewing the network as a general computation engine enables an exciting set of capabilities and applications. We have taken a modest step towards understanding the capabilities that an active network might provide with regard to the introduction of new services and their ....

Nygren, et al., "PAN: A High-Performance Active Network Node Supporting Multiple Mobile Code Systems", IEEE OpenArch, March 1999.

....applications to specify both performance and reliability targets. Opus then strives to build the lowest cost (or lowest overhead) overlay to meet the specified goals. 4 Related Work Our work on Opus is inspired by related efforts in a number of different fields. Research into Active Networks [1, 17, 27, 36] proposes moving computation into the network on a per packet level. We view our utility model as a logical culmination of the Active Network philosophy. That is, overlays push application level functionality to specific intermediate nodes in the network. However, the granularity of computation in ....

Erik L. Nygren, Stephen Garland, and M. Frans Kaashoek. PAN: A High-Performance Active Network Node Supporting Multiple Mobile Code Systems. In Proceedings IEEE OpenArch 1999.

....as its runtimes mature. It has facilitated the exploration of the design space at the cost of higher absolute performance. Higher performance implementations are a natural step towards deployment once the design and use issues are understood. One such effort that explores this direction is PAN [ Nygren, 1999 ] and a further approach would be to execute binary proof carrying code within an operating system kernel. In the remainder of this section, I describe the important features of the key classes in detail. This is done in a bottom up fashion, beginning with the node API available to capsules, ....

....goals. Proof carrying code, for example, is a promising technology, but is not mature enough to be of use. Software based fault isolation is a more mature technology, but offers a form of safety that is less well suited to frequent protection domain crossings than type safety. The design of PAN [ Nygren, 1999 ] a binary based active node that investigates performance but sacrifices security, illustrates this tension. At the other extreme, an implementation based on interpretation would have met security but not performance goals. It would have been too far removed from the long Subsequent to the ....

[Article contains additional citation context not shown here]

E. Nygren. PAN: A High-Performance Active Network Node Supporting Multiple Code Systems. In OPENARCH'99, New York, NY, March 1999. IEEE.

....of services in the network. 4 Related Work The Netlets architecture has common themes with many Active Network approaches exploiting mobile code. The most notable approaches featuring mobile code are ANTS [8] and the DAN [9] approaches, from which many other prototype extensions have been built [17, 18, 19]. The ANTS model takes on the code follows capsule approach. This scheme may fail in the case when the source node is attached via a wireless link, because wireless links, unlike most links in common wireline networks, are not necessarily bi directional. This approach is more tightly coupled with ....

Erik L. Nygren, Stephen J. Garland, and M. Frans Kaashoek, PAN: A High-Performance Active Network Node Supporting Multiple Mobile Code Systems IN PROCEEDINGS IEEE OPENARCH99, MARCH 1999

....shows that the gap is between 0 7803 7064 3 01 10.00 (C) 2001 IEEE IEEE OPENARCH 2001 200 for small 200 byte packets to 5 for packets over 1200 bytes. Here, too, the processing of the packet was independent of the packet length. In PAN, a capsule based active node built at MIT, Nygren et al. [12] measured the delay through several configurations of an active node. When only IP forwarding was used, the delay measured for a 128 byte packet was ###### # ###S , and for 1500 byte packet ####### # ####S . These numbers are very close to the ones measured in PLANet [8] The active evaluation ....

E. Nygren, S. Garland, and M. F. Kaashoek. PAN: A highperformance active network node supporting multiple mobile code systems. In OPENARCH'99, pages 78 --89, New York, NY, USA, Mar. 1999.

....CA 95014 USA (e mail: isidro pluris.com) A preliminary version of this paper was presented at ACM SIGCOMM 00 in Stockholm, Sweden, August 2000. network nodes. Many techniques provide such flexibility by allowing individual data packets to explicitly participate in routing decisions [21] 22] [34], 43] creating a large range of security and stability concerns. Others limit such functionality to specially authorized and authenticated control traffic, but either severely restrict functionality [45] require per packet processing on the forwarding path [49] or both [39] FIRE, the ....

.... likely that the traffic classes and advertised properties within TABLE I I ACTIVE NETWORKING COMPARISON System Technique Layer Domain Language Active Bridging [3] Device Bridging Caml Router Plugins [15] Device Services C ANTS [43] Capsule General Java PLANet [22] Capsule General PLAN PAN [34] Capsule General Java 5 Joust [21] Capsule General Java Smart Packets [39] Capsule Management Sprocket NetScript [49] Control NVN Management NetScript Tempest [45] Control ATM Management Ariel FIRE Control IP Routing Java each AS will differ, based upon the diverse interests of adjacent ....

[Article contains additional citation context not shown here]

E. Nygren, S. J. Garland, and M. F. Kaashoek. PAN: A high-performance active network node supporting multiple code systems. In Proc. IEEE OPENARCH '99, pages 78--89, Mar. 1999.

....and processing capacity in an intelligent manner. Further, new protocols that are developed after a router is deployed can be injected on the fly to evolve router behavior. Previous approaches in literature have investigated providing programmable services with Fast Ethernet line speeds [1] 2] 3][4][5] that implement interfaces similar to that specified in the NodeOS interface[6] for programmable execution environments. In the design of nanoProtean we reconsider some of the tradeoffs made in these projects. The paradigm shift is a goal to route traffic produced at 802.3z line speeds with ....

....thread from compromising the availability of these services. A. Resource Scheduling in Related Routing Research Related active networking solutions have used general purpose operating systems including NetBSD with POSIX thread runtime in user space[3] or a similar NodeOS configuration in Linux[4][5] or have optimized specific fast paths for a NodeOS[12] The nanoProtean programmability model is similar to that in Bowman, in that code is loaded from trusted parties. The differences are in making an OS design to provide scheduling similar to that in user level. The user level scheduling ....

E. Nygren, S. Garland, and M. Kaashoek, "Pan: A high-performance active network node supporting multiple mobile code systems," in OpenArch, 1999, pp. 78--89.

.... firewalls [8] and reduced network management traffic [21] Unfortunately, most of the active packet platforms have either restricted themselves to the control plane [21] had unacceptably low performance [25] 9] or have achieved reasonable performance only by sacrificing safety and security [17]. None has done an effective job of providing safe resource control. This has led to a widespread belief that active network processing in the data plane is fundamentally impractical. In this paper we show that, to the contrary, active packets can be of general use. To support this claim, we drew ....

....monitoring. With minor variations discussed in Section VI, SNAP uses the same techniques with the same benefits. Where existing systems generally fail is in controlling the resource utilization of active packets. Several systems use time tolive (TTL) counters to limit packet proliferation [7] [17], 25] and watchdog timers and allocation limits to terminate packets using too many local resources [21] 25] These approaches sacrifice safety because forced termination can be unsafe [5] PLAN [7] limits packet execution by restricting its expressibility so that all programs must terminate. ....

[Article contains additional citation context not shown here]

E. Nygren, S. Garland, and M. F. Kaashoek. PAN: A High-Performance Active Network Node Supporting Multiple Mobile Code Systems. In IEEE OPENARCH, March 1999.

....different capsule programs. If some aspect of the node programming interface, or the distribution protocol, needs to be changed, then the nodes would have to be changed, recompiled, and redeployed. In general, this reasoning applies to other active packet systems, like SmartPackets [19] PAN [17], and the packet programs of PLANet. 2.3.2 Netscript and Active Extension Systems Netscript is a system for writing composable protocol processors. The central abstraction in Netscript is called a box, which is conceptually some piece of code with a number of in ports and out ports; in ports ....

E. Nygren, S. Garland, and M. F. Kaashoek. PAN: A high-performance active network node supporting multiple mobile code systems, March 1999.

....packet forwarding. The application of capsules to packet forwarding is a question of what the ratio of computational resources is to the possible packet rate and bandwidth. The prototype systems discussed here are already suitable for links in the tens of Mbps range, while more advanced systems [21, 16], perform similarly to other softwarebased routers running on general purpose hardware, where hundreds of Mbps can be supported. Since capsules can provide sophisticated firewall capabilities, it is important to note that these results suggest that current firewalls could be made active without a ....

E. Nygren, S. Garland, and M. F. Kaashoek, "PAN: A High-Performance Active Network Node Supporting Multiple Mobile Code Systems," in Proceedings of the 1999 IEEE Second Conference on Open Architectures and Network Programming (OPENARCH'99), March 1999. 18

....through their software router, but the throughput data shows that the gap is between 200 for small 200 byte packets to 5 for packets over 1200 bytes. Here, too, the processing of the packet was independent of the packet length. In PAN, a capsule based active node built at MIT, Nygren et al. [12] measured the delay through several configurations of an active node. When only IP forwarding was used, the delay measured for a 128 byte packet was C(128) 50 S , and for 1500 byte packet C(1500) 130 S . These numbers are very close to the ones measured in PLANet [8] The active evaluation ....

E. Nygren, S. Garland, and M. F. Kaashoek. PAN: A highperformance active network node supporting multiple mobile code systems. In OPENARCH'99, pages 78 --89, New York, NY, USA, Mar. 1999.

....fail, in which case applications must recover the lost capsule in the normal manner. Details and analysis of this scheme are given in [29] We observe that ants could be used with any code distribution scheme in practice, for example, others have considered loading from nearby code servers [15, 4]. We believe, however, that our scheme has a number of desirable properties. It distributes code in an adaptable and scalable manner, and without an explicit setup phase. This means that the basic character of IP is retained. It does not rely on shortest path routes, which means that it can be ....

....by a factor of four, and it is likely that an in kernel implementation is faster by a factor of at least two again. These observations suggest that substantially faster implementations can be constructed without resorting to custom hardware and operating system support. As evidence of this, PAN [15] implements substantially the same architecture as ants with in kernel binary forwarding routines. It is able to saturate 100 Mbps Ethernet with 1 KB packets, almost an order of magnitude improvement. To understand capsule processing further, we profiled an ants node. The results are shown in ....

[Article contains additional citation context not shown here]

E. Nygren et al. PAN: A High-Performance Active Network Node Supporting Multiple Code Systems. In OPENARCH'99, New York, NY, Mar. 1999.

....route between communicating end hosts. The ANTS reference implementation of the design described was done by David Wetherall [Wet99a] in Java. A less known implementation of the same design is Erik Nygren s PAN system. This system runs in kernel or user space and both Java and C forwarding methods[Nyg99]. A user space PAN node runs on top of a traditional operating system. Multiple nodes connect together to form an overlay network and communication between the di erent nodes uses capsules that are encapsulated in UDP packets. An application that wishes to send PAN capsules instantiates objects ....

....and requires no modi cations to the receiver node; the sender node has to be modi ed to add functionality that keeps track of capsules in ight. We examined David Wetherall s ANTS design [Wet99a]and have looked at both Wetherall s reference implementation and Eric Nygren s PAN implementation[Nyg99]. The PAN implementation was chosen somewhat arbitrarily over the ANTS implementation for the prototype implementation. 4.1 Architecture There are at least three obvious places where a reusable congestion control component or library can be introduced into an application s communication code: 1. ....

E. Nygren, PAN: A High-Performance Active Network Node Supporting Multiple Mobile Code Systems. In Proc OpenArch'99.

.... mobile code firewalls [8] and reduced network management traffic [21] Unfortunately, most of the active packet platforms have either restricted themselves to the control plane [21] had unacceptably low performance [25] 9] or have achieved reasonable performance only by sacrificing safety [17]. None has done an effective job of providing safe resource control. This has led to a widespread belief that active network processing in the data plane is fundamentally impractical. In this paper we show that, on the contrary, active packets can be of general use. To support this claim, we drew ....

....With minor variations discussed in Section VI, SNAP uses the same techniques with the same benefits. Where existing systems generally fail is in controlling the resource utilization of active packets. Several systems use time to live (TTL) counters to limit packet proliferation [7] 25] [17] and watchdog timers and alloca 2 tion limits to terminate packets using too many local resources [25] 21] These approaches sacrifice safety because premature termination can be unsafe [5] PLAN [7] limits packet execution by restricting its expressibility so that all programs must terminate. ....

[Article contains additional citation context not shown here]

E. Nygren, S. Garland, and M. F. Kaashoek. PAN: A HighPerformance Active Network Node Supporting Multiple Mobile Code Systems. In IEEE OPENARCH, March 1999.

....modules. During execution, when a program (from a capsule) refers 3.3 ANs Enabling Technologies 50 to unknown functions, the processing is suspended, a query made to the code server, and the required modules are loaded on a demand basis. A kernel based capsule approach called PAN was proposed in [151]. The performance overhead documented for the processing of a capsule (1500 bytes on a Pentium Pro 200Mhz running linux) was shown to be as little as 13 . Their results also showed that the use of Java bytecode increased the overheads by three fold. Apart from that, the PAN architecture enables ....

....needed. The time in which a node becomes active is not determined a priori, and its invocation depends on the state of the communication, for example after a migration. The performance of ANs is being investigated and increasingly better performance architectures have emerged. For example, in PAN [151] the computational overhead is only 13 on a Pentium Pro 200 MHz running Linux. The Bowman [161] node operating system for ANs is able to sustain 100Mbps throughput while forwarding IP packets over fast Ethernets. No work has yet implemented and investigated the performance of ANs on a dedicated ....

E. L. Nygren, S. J. Garland, and M. F. Kaashoek, \PAN:a high performance active network node supporting multiple mobile code systems," in IEEE OPENARCH '99, Mar. 1999.

....determine whether we can choose a new tradeoff point resulting in higher practicality than IP, by adding significant flexibility without sacrificing too much safety or efficiency. 3 The First Generation This section examines the main existing active packet systems: ANTS [38] PLAN [11, 13] PAN [24], Smart Packets [28] ALIEN [1] M; 33] and SafetyNet [34] We will describe each system and consider how it fits into our practicality framework. We will examine how each system trades off along the three axes of safety, efficiency, and flexibility and evaluate its strengths and weaknesses. ....

....application specific routing [13] multicast [10] and virtual private networks [22] One awkward point, however, is that the resource bound conservation properties make it difficult (from a programmer s point of view) to apportion a packet s resource bound among multiple children. 3. 3 PAN PAN[24, 25] is follow on project to ANTS, also developed at MIT. The main question Nygren et al. address is: are the computational overheads of providing active processing too high to ever achieve practical performance Fortunately for us, the answer was no. PAN achieves its high performance through the ....

[Article contains additional citation context not shown here]

E. Nygren, S. Garland, and M. F. Kaashoek. PAN: A highperformance active network node supporting multiple mobile code systems. In Proceedings of the 1999 IEEE Second Conference on Open Architectures and Network Programming (OPENARCH'99), March 1999.

....node design was developed and implemented as a prototype. The reason for the development of an own implementation 2 can be found in the lack of simple, ready to use experimentation platforms for active network services. Available systems are either using proprietary operating systems (e.g. [8, 14, 13]) rely on significant extensions of common operating systems to provide highly specialized service execution environments within kernel context [5] or, at least, use proprietary programming languages [7] Further, the AMnode design was necessary to allow for the integration of both software and ....

E. Nygren, S. Garland, and M. Kaashoek. PAN: A High-Performance Active Network Node Supporting Multiple Mobile Code Systems. In IEEE OPENARCH'99, New York, March 1999.

....do not export a node OS interface over which different EEs can be built 9 . This architectural difference between Bowman and Router Plugins clearly exposes the performance versus generality tradeoff inherent in the design of extensible router platforms. The aim of Practical Active Network (PAN) [12] project at MIT is to build a high performance capsule based active node that is based on the ANTS [4] framework. Experiments have shown that the forwarding performance of capsules containing Java [13] byte code is dominated by overhead incurred due to execution within the Java virtual machine. ....

Erik L. Nygren, Stephen J. Garland, and M. Frans Kaashoek, "PAN: A High-Performance Active Network Node Supporting Multiple Mobile Code Systems," in Proceedings of IEEE OpenArch '99, March 1999, pp. 78--89.

....ANTS implementation was done in Java, relying heavily upon the safety properties of the language and requiring heavyweight veri cation at each hop. Indeed, this user space interpretation allowed under 20 Mb s throughput in practice [16] A follow on project to ANTS was the PAN mobilecode platform [9], which provides in kernel support for mobile code. Nygren et al. demonstrate line rates (over 90 Mb s) when dynamically loading x86 object code. However, this loading is done in an unsafe manner, thus making it possible for an active packet to crash the node. While achieving high enough ....

E. Nygren, S. Garland, and M. F. Kaashoek. PAN: A High-Performance Active Network Node Supporting Multiple Mobile Code Systems. In Proceedings of the 1999 IEEE Second Conference on Open Architectures and Network Programming (OPENARCH'99), March 1999. 9

....rtheraggravatedbylimitedmaintenance (bugfixes)andsupport,usersofaresearchprototypeOS areforcedtotradeoffgoodsupportforthepartstheyareinterestedinfortheenhancednetwork support. Anumberofarchitecturesandservicemodelshavebeenproposedfornetworknodessuppor tingactiveandprogrammablenetworking [5,6,7,8,9,10,11,12].Ofthose[5,7]and[9]operate attheuserlevel, 8]providesprogrammabilitysolelyatthekernel, 6,11,12]useacombination ofauserlevelenvironmentandaproprietarykernel,and[10]usesaproprietarylanguageandOS levelruntimesupport.Whereastheuserlevelexecutionenvironmentsarereallyabovetheinte rfaceofthenode ....

....support. Anumberofarchitecturesandservicemodelshavebeenproposedfornetworknodessuppor tingactiveandprogrammablenetworking [5,6,7,8,9,10,11,12] Ofthose[5,7]and[9]operate attheuserlevel, 8]providesprogrammabilitysolelyatthekernel,[ 6,11,12]useacombination ofauserlevelenvironmentandaproprietarykernel,and[10]usesaproprietarylanguageandOS levelruntimesupport.Whereastheuserlevelexecutionenvironmentsarereallyabovetheinte rfaceofthenode soperatingsystem,kernellevelprogrammabilityismoresuitedforvendor ....

[Article contains additional citation context not shown here]

ErikL. Nygren,StephenJ.Garland,andM. FransKaashoek,"PAN:A High-Performance ActiveNetworkNodeSupportingMultipleMobileCodeSystems,"In proceedingsof OpenArch '99,pp.78-89.NewYork,NewYork.March27,1999.

No context found.

E.L. Nygren, S.J. Garland, M.F. Kaashoek, PAN: a high-performance active network node supporting multiple mobile code system, Proceedings of the Second IEEE Conference on Open Architectures and Network Programming (OpenArch'99) March (1999).

No context found.

E. Nygren, S. Garland, and M. F. Kaashoek. PAN: A high-performance active network node supporting multiple mobile code systems. In OPENARCH'99, pages 78-89, New York, NY, USA, Mar. 1999.

No context found.

E. Nygren et al. Pan: A high-performance active network node supporting multiple code systems. Proceedings of OPENARCH'99, 1999.

No context found.

E.L. Nygren, S.J. Garland, M.F. Kaashoek, PAN: a high-performance active network node supporting multiple mobile code system, Proceedings of the Second IEEE Conference on Open Architectures and Network Programming (OpenArch'99) March (1999).

No context found.

E. Nygren, S. Garland, and F. Kaashoek. PAN: A high-performance active network node supporting multiple mobile code systems. In IEEE OpenArch, pages 78--89, New York, NY, March 1999.

No context found.

NYGREN, E. L., GARLAND, S. J., AND KAASHOEK, M. F. PAN: A High-Performance Active Network Node Supporting Multiple Mobile Code Systems. In Proc. of OpenArch'99 (1999).

No context found.

E. Nygren et al. Pan: A high-performance active network node supporting multiple code systems. Proceedings of OPENARCH'99, 1999.

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E. Nygren, S. Garland and M. F. Kaashoek, "PAN: A HighPerformance Active Network Node Supporting Multiple Mobile Code Systems", presented at Proceedings OPENARCH'99, 1999.

No context found.

Erik L. Nygren, Stephen J. Garland, and M. Frans Kaashoek. PAN: A HighPerformance Active Network Node Supporting Multiple Mobile Code Systems. In Proceedings of the 2nd Workshop on Open Architectures and Network Programming (OPENARCH'99), pages 78-89, March 1999. 151

No context found.

E. L. Nygren et al., "PAN: A High-Performance Active Network Node Supporting Multiple Mobile Code Systems," OPENARCH '99, Mar. 1999, pp. 78-89.

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