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GENERIC PROTOCOL FOR NETWORK MANAGEMENT DATA COLLECTION AND DISSEMINATION Cho-Yu Jason Chiang, Anthony McAuley, Dana Chee, Larry Wong Applied Research, Telcordia Technologies 445 South Street, Morristown, NJ 07960 ABSTRACT1 YAP is a protocol designed to efficiently and robustly relay network configuration states of nodes to a designated node that collects and stores the configuration states of all the nodes. Once the configuration states from the nodes are collected, any application can query the information to perform its own specific function. For example, a GUI application can query the database to display the logical topology of the networks. Also a Configuration Manager can query the database to decide how to reconfigure the network. We describe how YAP was integrated with protocols designed to auto -configure IP-related attributes of nodes (using DRCP and DCDP). INTRODUCTION The dynamicity of mobile ad hoc networks calls for the automation of the network configuration process to allow efficient, transparent, and convenient network access from the perspective of users. Although DHCP [6] was designed to provide network access and could be used to configure a roaming node that joins a network, it was found to be inefficient in terms of both configuration time and bandwidth usage [1]. Furthermore, in highly dynamic wireless networking environment such as tactical networks, it is crucial to extend beyond the notion of configuring nodes to configuring networks so that not only the node addresses (IP suffixes), but also the network addresses (IP prefixes) and network services information (such as who hosts the DNS server) can be dynamically configured. DCDP (Dynamic Configuration Distribution Protocol) [5] and DRCP (Dynamic and Rapid Configuration Protocol) [1] work in tandem to auto-configure IP networks. The aim is to eliminate manual configuration effort from human administrators and enable automatic network configuration and reconfiguration. The network configuration process includes distributing IP address pools and subnet masks to form inter-connecting subnets, assigning IP-related

configuration to nodes, activating and announcing network services such as DNS, setting up routing tables and starting routing software for packet forwarding. By automating the network configuration process, DCDP and DRCP protocols speed up this process in many orders of magnitude as compared to the manual effort. Due to the distributed nature of DCDP and DRCP, once nodes have received configuration information to start network operations, it is important to collect configuration results from all the nodes to verify the efficiency and consistency of the auto-configuration process and allow applications to use the collected global state to perform their specific missions. For example, Bandwidth Broker can determine the appropriate bandwidth allotment for different classes of traffic on a link when admitting incoming traffic flows. BACKGROUND In the past, the logic of collecting the network configuration information was built into the module that was in charge of distributing and/or displaying the configuration information. Clearly, the major shortcoming of the above approach is that it doesn't separate distinct functionalities into separate components. The Yelp Announcement Protocol (YAP) is designed for nodes to relay configuration information to a centralized information collecting node. It is a client-server protocol that enables collecting and disseminating information in a distributed environment. Therefore, DRCP and DCDP can rely on the relaying service to deliver configuration states of nodes to a centralized repository, and applications such as GUI can query the repository for information. With the introduction of YAP, we have a clean and unified interface that segregates components of distinct functionality. Also note that the functionality of YAP is orthogonal to that of auto-configuration protocols. The decoupling allows it to work with any other network management application that needs data collection and dissemination services. YAP OVERVIEW

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This work was supported in the Advanced Telecommunications & Information Distribution Research Program (ATIRP) Consortium sponsored by the U.S. Army Research Laboratory under the Federated Laboratory Program, Cooperative Agreement DAAL01-96-2-0002. The U.S. Government is authorized to reproduce and distribute reprints for Government purposes notwithstanding any copyright notation thereon.

YAP is a robust, scalable, rapid, low-overhead, lightweight (small state-keeping overhead), and event-driven information relaying protocol. The simplicity of its protocol state transitions makes it robust and rapid; the small message headers and message aggregation function

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make the overhead low; the state -keeping overhead is none or small, depending on the roles of the entities; and finally, the delay of relaying messages are small and in most situations messages are relayed immediately after they are received. ARCHITECTURE YAP is designed for collecting and disseminating the configuration states of a distributed set of nodes. We will discuss the part that pertains to collecting configuration states and storing them in the repository first, and then move on to discuss obtaining the global states through querying YAP server.

timeout event that triggers the flush of all buffered messages. Let's use Figure 1 to illustrate the function of YAP relay. There are two different styles of lines, one consists of '|' and the other consists of ':'. The former denotes message relays that result from the regular timeout events and the latter denotes message relays for non-routing interfaces. In this figure, both YAP relay1 and YAP relay3 have one routing and one non-routing interfaces, YAP relay0 has only one routing interface and is on the same host of the YAP server, YAP relay3 and YAP relay5 each has only one non-routing interface while YAP relay4 has two nonrouting interfaces.

COLLECTING CONFIGURATION STATES

THE ROLE OF YAP SERVER

There are two types of YAP entities--YAP relays and YAP servers. Within one single administrative domain, there is only one YAP server and each node will host a single YAP relay. A YAP relay may receive YAP messages from the node that hosts it, or from other YAP relays. The received messages may contain relaying instructions or current configuration states of the reporting entities. YAP relays listen on UDP port 4567 and YAP server listens on UDP port 2550. The typical communications between YAP relays and a YAP server are illustrated in Figure 1. +---------------+ | Configuration | | State | | Repository | +---------------+ ^ | v +-------- + | YAP | | Server | +-------- + ^ ^ ^ / | \ / | \ / | \ +-------- + + -------- + + -------- + | YAP | | YAP | | YAP | | Relay1 |::>| Relay0 |