MIB-ORIENTED PROTOCOL FOR HIGHLY EFFECTIVE HTTP MANAGEMENT PROCEDURES

Description

[0001] The invention relates to a method for transmitting data packets between a network-monitoring network management station and network devices of the network according to claim 1.

[0002] A network management station is used to monitor, remotely control, and configure network devices, as well as to detect and report errors. This station uses a network protocol to control and monitor the network devices from a central location. The Simple Network Management Protocol (SNMP) has become the standard in practice. This protocol defines the structure of the data packets that can be sent and the communication flow between the network management station and the connected network devices. Monitoring is performed using agents on the network devices. These agents can be programs running directly on the monitored devices or hardware components that perform the same task.

[0003] For communication between the network management station and the network devices, the Simple Network Management Protocol defines six different data packets that can be sent (get-request, get-nextrequest, get-bulk, set-request, get-response and trap).

[0004] For data exchange between the network management station and network devices, not only is the prescribed protocol required, but also a database within the respective network device, which, in the context of SNMP, is referred to as the Management Information Base (MIB). This MIB is a description containing definitions of management information that can be used to remotely control, monitor, and configure a network-connected device. As already described above, SNMP is used in practice for these functions, as this protocol has established itself as a global standard. The management information is called managed objects, although strictly speaking, a managed object is not an actual data value, but rather a description of one.This means that the Management Information Base of a network device does not contain any data, but only describes where this data can be found in the network device and what it looks like.

[0005] In practice, however, it has been found that the transmission of data packets at the request of a network management station to the network device and back is limited to the largest frame size permitted for a single frame of the data packet in the network (the so-called maximum transmission unit, MTU). For this reason, queries of large volumes by the network management station, especially queries for large data blocks, lead to multiple consecutive queries by the network management station and responses from the requested network device, resulting in long waiting times, high packet loss, or similar disadvantages, all of which are critical aspects.

[0006] As an example from the state of the art, the following is shown: Figure 2 to refer to the example in which a well-known SNMP table query is shown. The network management station (SNMP command requester) wants to request a large amount of data (large query table) from a network device (SNMP sender), which is to be transmitted back after the query. This cannot be done in a single query step, but rather, as shown in the example in Figure 2 A total of six steps (left illustration of the Figure 2 ) necessary.

[0007] Depending on the desired large query table and its content, it may be possible to request and submit the desired data in a single response message (right-hand representation of the Figure 2However, this is rarely or never the case nowadays, as the data required for controlling, configuring, and monitoring network devices by the network management station has become so extensive that it can no longer be transmitted in a single response message. Furthermore, reference is made here to US patent US7739362 B1, which describes a representational document format (HTML template) and interface (HTTP, SNMP) intended for browsing and displaying MIB objects in a web browser or application. European patent application EP1154601 A1 describes an MIB interface based on SNMP commands. This interface processes queries similarly to SNMP and traverses the MIB tree using preorder logic.

[0008] The invention is therefore based on the objective of improving a method for transmitting data packets between a network-monitoring network management station and network devices of the network device, without restrictions on querying, compiling the queried data and transmitting the compiled data back.

[0009] This problem is solved by the features of claim 1.

[0010] According to the invention, the network management station accesses a management information base (MIB) of a network device by means of a configurable command and retrieves data packets that correspond to the command's configuration. While in the prior art, particularly when using SNMP, not only the number but also the content of the commands is fixed, the configurable command according to the invention now makes it possible to retrieve precisely the data on the network device and to compile and transmit it to any desired extent. This advantageously eliminates the restrictions imposed by SNMP regarding the number and content of its commands. The protocol according to the invention, which can also be referred to as a MIB-oriented protocol (MOP), is therefore not subject to any such restrictions, particularly data size limitations, as those imposed by SNMP.Therefore, it is advantageous to transmit the complete query, based on an arbitrarily configurable command, before the server processes it. Complete queries allow the server to optimize data processing, such as setting database locks, pipeline operations, and the like.

[0011] In the queries of table data from the MIB of the network device according to the invention, the MOP according to the invention enables the setting up of a filter for a further reduction of network bandwidth and optimization of data processing, since precisely those data from the network device can be requested, compiled, and transmitted that correspond to the configured command, which can, in particular, take the available network bandwidth into account. This is not possible with an equivalent SNMP bulk query, since, as already described, a large number of individual queries and the transmission of partial database contents must take place. With an SNMP bulk query, the desired table cannot be retrieved in a single query / response message exchange, as this protocol does not define an end-object identifier for the query and only supports an initial identifier and the number of repetitions (see also Figure 2 ).

[0012] In contrast, the MOP according to the invention forms the MIB structure for an assignment with keys and values, wherein the keys represent the available nodes and the values ​​represent the available branches of these nodes. These nodes can be retrieved in a single query via the MOP according to the invention.

[0013] According to the current state of the art, the Management Information Base (MIB) is a data model that is very often linked to the widely used Simple Network Management Protocol (SNMP), a worldwide standard protocol for managing devices on IP networks.

[0014] The solution according to the invention relies on a method for transferring said MIB data, which is not subject to the limitations of current implementations (i.e., SNMP versions 1-3).

[0015] The MOP according to the invention offers the advantages of reduced network latency compared to SNMP. It also results in minimal network traffic compared to SNMP. Furthermore, it supports common HTTP use cases and allows for a seamless transition from MIB-based SNMP implementations to the MOP method for transferring data. Additionally, it advantageously supports enhanced error handling compared to SNMP.

[0016] In a further development of the invention, it is provided that the network management station accesses the respective network device via HTTP. While the established and standard SNMP uses UDP (User Datagram Protocol) as the transmission protocol and a binary data format, the MOP according to the invention enables lightweight, HTTP-based client frameworks for accessing the MIB information.

[0017] The MOP according to the invention thus advantageously enables a simple transition from MIB-based SNMP implementations. Since the MIB access layer is often decoupled from the SNMP layer, implementers can directly access the MIB data to form a response after the MOP. The MOP server can preferably run as an HTTP service and utilize the existing security and load balancing functions of the HTTP server.

[0018] In a further development of the invention, the requested data is provided by the Management Information Base (MIB) in a text data format. This advantageously allows modern web browsers and web APIs to implement an MOP client. While the basic protocol operation is based on the RPC (remote procedure call) definition NETCONF, the MOP according to the invention defines its own data model and data representation layer for representing the MIB data. Examples of a text data format are XML or JSON, although this list is not exhaustive. Since the MOP according to the invention enables a simple transition from MIB-based SNMP implementations, the data format (text data format) was chosen to allow a direct mapping, in particular a 1:1 mapping, of the hierarchical MIB structure to the MOP data.

[0019] A further advantage is that the MOP according to the invention allows for the free assignment of error codes either to protocol operations or to MIB data objects, thus advantageously overcoming the limitation that SNMP response messages only permit a limited selection of error status codes. A direct mapping, in particular a 1:1 mapping of SNMP to MOP error codes, is possible and can be readily applied by implementers. To support extended error handling, the element containing the data of an MIB object can be extended.

[0020] The following section briefly refers to the figures for clarification. Figure 1 shows an example of a network transport layer. Figure 2As described at the beginning, this shows an example of a table query of a network device by a network management station based on SNMP. The method according to the invention makes it possible to query exactly the requested data (and thus not have to query more or less data). Therefore, advantageously, no queries beyond the MIB nodes are made (see Figure 2 , SNMP "part of next table" and filtering options). In Figure 3 An MOP table query according to the invention is shown, wherein it is directly recognizable that the query can be carried out by means of a request based on a configurable command, whereby the compilation of the desired data (here for example table one and table two) and the compiled data are transferred back from the network device to the network management station in one step. Figure 4 shows a comparison of the data according to MIB and the MOP according to the invention. Figure 5Finally, a MOP data model (XSD schema) shows the invention.

Claims

1. Method for transmitting data between a network management station monitoring a network and network devices of the network, comprising the following method steps: installing agents on the network devices, wherein the network management station communicates with the respective agent of a network device using commands; the network management station accessing a management information base, MIB, of a network device by means of a configurable command in the form of an MOP query, wherein the MOP query is a query according to an MIB-oriented protocol, MOP; and retrieving data corresponding to the configuration of the command, wherein data are transmitted in a single MOP response message by means of the one configurable command, wherein the MOP query is effected as an MOP table query, wherein the query is effected by means of a request based on the configurable command, as a result of which the compilation of the desired data and the compiled data are transmitted back from the network device to the network management station in one step and precisely the queried data are supplied in the response message.

2. Method according to Claim 1, characterized in that access is carried out in a HTTP-based manner.

3. Method according to Claim 1 or 2, characterized in that the requested data are supplied by the management information base in a text data format.

4. Method according to Claim 3, characterized in that the MOP query comprises the setup of a filter, since exactly those data which correspond to the configured command are requested, compiled and transmitted from the network device.

5. Method according to one of Claims 1 to 4, characterized in that a plurality of tables can be queried and received in each case in an MOP query and response message.