HK1158401B - Systen for diagnosing cable and method and system for port configuration of ethernet - Google Patents

Description

Cable diagnostic system and method and system for configuring Ethernet port

The application is a divisional application of Chinese invention application with application date of 2007, 12 and 14, application number of 200710160257.3, entitled "Cable diagnosis System and method and System for Ethernet Port configuration".

Technical Field

The present invention relates to systems and methods for network cabling, and more particularly to diagnostics of cabling infrastructure.

Background

The development of computer networks has facilitated an increase in network cable usage. Initially, 10BASE-T ethernet may be supported using a type 3 cable with a "telephone grade" cable. These inexpensive twisted pair cables support distances of up to 100 meters.

As network speeds have increased, category 3 cables have been unable to support higher transmission speeds. Thus, category 5 cable is used to support fast Ethernet such as 100 BASE-T. Today, with the next step in network cable innovation, category 6 cables for supporting gigabit ethernet and higher speeds are emerging.

The evolution of the network cable infrastructure has also been driven throughout the evolution of transmission speeds. The development of network cable infrastructure often drives new network cables into the existing infrastructure. The cable infrastructure that arises in such a case is therefore similar to a patchwork of different types of cables. Only new arrangements are possible with a wiring infrastructure employing a single type of cable.

In the development of cabling, the most typical result it has resulted in is that its network cabling infrastructure comprises multiple generations of network cable types. For example, an office may have a mix of category 3, 5, and 6 network cables distributed throughout the office. This is due to the expense involved in removing old network cables and the fact that these old network cables are still available for a particular subset of applications. Finally, the mix of network cables presents an important challenge in ensuring that the correct cable type is used in a particular application. Typically, the determination of the cable type requires manual cable testing. This process is time consuming and expensive. There is a need for a mechanism that can implement automatic detection of network cable types.

Disclosure of Invention

A system and/or method for diagnosing a wiring infrastructure using a PHY, substantially as shown in and/or described in connection with at least one of the figures, as set forth more completely in the claims.

According to one aspect of the present invention, a cable diagnostic system includes:

a cable sensing component in the PHY for measuring an electrical characteristic of an ethernet cable connected to the PHY;

a controller for determining a type of the Ethernet cable based on the measured electrical characteristic, the controller operable to generate a report of the determined Ethernet cable type.

Preferably, the cable detection assembly measures an insertion loss of the ethernet cable.

Preferably, the cable detection component measures crosstalk of the ethernet cable.

Preferably, the cable detection assembly measures the length of the ethernet cable.

According to one aspect of the invention, an ethernet port configuration system comprises:

a cable sensing component in the PHY for measuring an electrical characteristic of an ethernet cable connected to the PHY;

a controller for determining the type of the Ethernet cable based on the measured electrical characteristic, the controller being operable to configure operation of the Ethernet port based on the determined Ethernet cable type.

Preferably, the cable detection assembly measures an insertion loss of the ethernet cable.

Preferably, the cable detection component measures crosstalk of the ethernet cable.

Preferably, the cable detection assembly measures the length of the ethernet cable.

Preferably, the controller determines whether an ethernet port is available.

Preferably, the controller changes a parameter of the ethernet port.

Preferably, the controller changes the circuitry of the ethernet port.

Preferably, the cable detection assembly measures the length of the ethernet cable.

According to an aspect of the present invention, a method for configuring an ethernet port includes:

upon initializing an ethernet port, determining a type of cable connected to the ethernet port based on the measured electrical characteristics; and

configuring the Ethernet port based on the determined cable type.

Preferably, the determining comprises measuring an insertion loss of the ethernet cable.

Preferably, the determining comprises measuring crosstalk of the ethernet cable.

Preferably, the configuring comprises activating the ethernet port.

Preferably, the configuring comprises deactivating the ethernet port.

Preferably, the configuring comprises adjusting parameters of the ethernet port.

Preferably, the configuring comprises adjusting circuitry of the ethernet port.

Preferably, the method further comprises generating a report of the determined cable type.

Drawings

In order to illustrate the manner in which the above-recited and other advantages and features of the invention are obtained, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:

FIG. 1 is a schematic view of an embodiment of a system for determining a cable type using cable characterization information;

FIG. 2 is a flow chart of a measurement process;

FIG. 3 shows a cable pair that may be shortened on the line side or transceiver side of a transformer;

FIG. 4 is a schematic illustration of insertion loss measurements for category 3 and category 5 cables;

FIG. 5 is a schematic illustration of near end crosstalk testing of category 3 and category 5 cables;

fig. 6 is a flow chart for using cable type information.

Detailed Description

Various embodiments of the invention are discussed in detail below. It is to be understood that the specific embodiments have been discussed for illustrative purposes only. It will be apparent to those skilled in the art that other elements and configurations may be used without departing from the spirit and scope of the invention.

The determination of the cable type has a significant impact on the use of the cable for a particular application. For example, it is determined that one cable is of category 5, which would be available for 100BASE-T fast Ethernet applications. Analyzing the cable infrastructure in relation to the cable type is critical to ensure that the cable infrastructure is properly used. It is therefore a feature of the present invention to systematically analyze the cable infrastructure in an automatic mode.

According to the present invention, the cable infrastructure (infrastructure) is analyzed using line characteristics (line characteristics) measurements by PHY (physical layer). Fig. 1 illustrates an embodiment of a system for measuring line characteristics in a network cable. As shown, measurement system 100 includes PHYs 130-1 through 130-N, each of which may be connected to Ethernet switch 120. Each PHY may also be connected to CPU 100, with only a single connection from CPU 110 to PHY 130-N shown for simplicity.

In one embodiment, CPU 110 is integrated with Ethernet switch 120 and PHYs 130-1 through 130-N on a single chip. In another embodiment, Ethernet switch 120 and PHYs 130-1 through 130-N are integrated on a single chip separate from CPU 110 and may communicate with CPU 110 through a series of interfaces.

The operation of measurement system 100 in implementing the principles of the present invention may be described with reference to the flow chart shown in FIG. 2. As shown, the flow of FIG. 2 begins at step 202, where a transceiver in the PHY 130-N measures a line characteristic of a cable connected to the PHY 130-N. In one embodiment, the measurements may be performed during echo cancellation convergence performed by an echo canceller module controlled by CPU 110 to determine insertion loss, crosstalk, and cable length. In step 204, the line characteristic measurement values obtained by the transceiver are sent to the CPU 110.

In step 206, the cable type (e.g., category 3, 5, 6, 7, etc.) is determined using the line measurement data. In one embodiment, the length of the cable is measured in addition to the cable type. In various embodiments, these determinations may be performed by the CPU 110 or any other system component responsible for diagnosing or reporting the cable type. After determining the cable type (and possibly cable length), the system may then determine its impact on system configuration and/or operation in step 208. Examples of such effects on system configuration and/or operation are described in greater detail below.

As described above, one or more characteristics of the ethernet cable, such as insertion loss, crosstalk, and length, may be measured to determine the cable type. It should be noted that insertion loss, crosstalk, and length measurements of ethernet cables are one example of characteristics that may be used to estimate cable type. Other measurements may be used without departing from the spirit and scope of the present invention.

In general, different cable types meet their own defined insertion loss standard over a range of frequencies. The electrical signals transmitted over the cable experience varying degrees of attenuation depending on the type of cable, and the insertion loss is a function of frequency and cable length, well defined for each cable type. To determine the cable type, the system may send one, multiple, or continuous pulses having predetermined frequency components into the cable. At the receiving end, the system can measure attenuation magnitude (attenuation) and phase distortion, and then combine this information with the cable length to determine the cable type.

In one embodiment, the link partner (link partner) may be turned off and the cable pair disconnected from the line side or the opposite (transceiver) side of the transformer. In this case almost all the incidental pulses may be retro-reflected to the transmitting end with the same polarity and these pulses will experience an insertion loss corresponding to twice the cable length. Figure 4 shows the insertion loss of a category 3 cable and a category 5 cable that can be used to measure 100 m.

In another embodiment, the link partner may be turned off and the cable pair shortened from the line side or the opposite (transceiver) side of the transformer. As shown in FIG. 3, where A + is shorter than A-. In this case, almost all the incidental pulses may be retro-reflected to the transmitting end with opposite polarity, and these pulses will experience an insertion loss corresponding to twice the cable length.

In another embodiment, the link partner may be closed and the two cable pairs disconnected and shorted from the other pair to form one loop (e.g., A + shorted to B + and A-shorted to B-). This can be done on the line side or the opposite (transceiver) side of the transformer. In this case almost all of the accompanying pulses can be sent back to the different pairs of transmitting ends and these pulses will experience insertion losses corresponding to twice the cable length.

In another embodiment, the link partner may be temporarily turned on to send a predetermined pulse. In this case, these pulses will experience insertion losses corresponding to the length of the cable.

Crosstalk is similar to insertion loss, with different cable types meeting their own defined crosstalk standards over a range of frequencies. The electrical signals transmitted over the cable inject different noise into adjacent pairs depending on the type of cable. Crosstalk is a function of frequency and cable length and is well defined for each cable type. To determine the cable type, the system may send one, multiple, or continuous pulses having predetermined frequency components into the cable. At the receiving end, the system can measure the attenuation magnitude and phase distortion, and then combine this information with the cable length to determine the cable type.

There are two types of crosstalk: near-end crosstalk (NEXT) and far-end crosstalk (FEXT). For NEXT, noise injection from one or more local transmitters, and for FEXT noise injection from one or more remote transmitters, whether NEXT or FEXT or a combination thereof, can be used to determine the cable type. Fig. 5 shows an example that can be used to measure category 3 cables and category 5 cables.

In one embodiment, the cable length may be determined directly using a Time Domain Reflectometer (TDR). In an alternative embodiment, the cable length may be determined directly based on data generated during the measurement of the insertion loss using the round trip of the injected signal. Here, the time interval for transmitting and receiving the above-mentioned pulses is linearly proportional to the cable length. The cable length is calculated by multiplying the propagation speed and the time interval and then dividing by 2 to calculate the round trip delay.

The system may use the cable type determined based on the PHY measurements in a number of ways. The cable type may be used, for example, in diagnostic performance, or as part of a dynamic setup or run process.

The principles of the present invention may be applied in general diagnostics of wiring infrastructures. For example, it is often important to be suitable for identifying cables in a wiring closet or data center prior to use. Manual completion can be a time consuming task if hundreds or thousands of network cables need to be identified. Manual identification is prone to error if not performed and/or recorded in a systematic manner.

The diagnostic tool of the present invention will be deployed in the wiring infrastructure and determine the type of cable in a systematic manner. For example, based on measurements such as insertion loss and crosstalk, the diagnostic tool may classify cables connected to a chassis. A cable type report may then be provided to alert a technician of the type of wiring infrastructure. Cables that do not meet certain specifications can then be "cleaned" without difficulty. It should be noted that this diagnostic tool may also be used to identify any portion of a link of a particular cable type.

More generally, it is a further feature of the present invention that such a diagnostic tool can be incorporated as part of a dynamic configuration or operational process. An example of such a dynamic configuration or run process is shown in the flow chart of fig. 6.

As shown, the process begins at step 602, where the ethernet transceiver measures the line characteristics of the cable connected to the port. In one embodiment, this line characteristic may include insertion loss, crosstalk, and length. In step 604, the cable type may be identified based on these measured line characteristics. Next, a determination is made as to whether the identified cable type meets the base specification at step 606.

Consider, for example, its application, such as 10GBASE-T as defined by IEEE 802.3 an. This specification includes the minimum requirements required to use category 7 ethernet wiring. In this example, determining that its cable type is a type 7 or higher means that the cable connected to the port is included in the prescribed cable specification. Next, in step 612, this type 7 or higher determination allows 10GBASE-T communications to be made over the cable connected to this particular port.

In general, the determination at step 606 may be viewed as a threshold determination that specifies whether a given application may be executed on a previously unacknowledged cable. In other words, there is no need to identify the cable type before connecting it to the port. Instead, measurements of line characteristics are used to identify the type of cable after it is connected to the port. This determination will then be used to determine whether the port is available. This port will be available if the cable is compliant with its specification. If the cable does not meet its specification, this port will not be available. In this case, an alarm notification may also be generated that the cable connected to the port is not compliant with the specifications of a given application.

In one embodiment, identification of the cable type may also be used for configuration or operation of the port. In this case, determining that the cable does not meet the base specification will result in a second determination at step 608 that a lower cable type is available for the application at step 608. In general, this second determination is useful when the standard specification for a given application is based on worst case assumptions. For example, the standard specification is based on the worst estimate of the cable length. Here, over shorter distances, specifications designed to support communications over 100 meters of cable may operate with poorer quality over shorter distances.

In view of this possibility, the determination at step 608 may be designed such that the use of existing cable infrastructure is optimized. Even where a given cable does not conform to conservative specifications, the principles of the present invention allow additional analysis to be performed to determine whether a given cable connected to a port is available in a particular application setting, instead of relying excessively on cable performance characteristics based solely on cable type.

It should be appreciated that the particular component performing the analysis in step 608 may depend on a given application. In a simple embodiment, this analysis may be based on a simple determination of additional factors, such as the use of a length to define a poor quality cable. Here, cables that do not comply with the conservative specification for category 7 cables may also be restricted from use when their length is less than a predetermined threshold (e.g., 50 meters).

Returning to the flowchart shown in FIG. 6, if the determination at step 608 indicates that the cable is not available for the given application, then an alarm will be generated. This alarm is typically designed to notify a given port of non-compliance with specifications. In one embodiment, the system may be designed to still attempt to use the cable on that interface to see if it supports a given application.

If the determination at step 608 indicates that a cable that does not conform to the standard specification is still available for a given application, then an appropriate configuration for the port may be defined at step 610. It should be appreciated that the particular port configuration may depend on the particular application. In one example, the port configuration may simply include recording the type of cable used at the port. In another example, the port configuration may also include adjustments to circuitry or other parameters on the port to accommodate the identified cable type. After the appropriate configuration is identified, the application may continue to run in step 612.

As described above, various cable characteristics obtained using PHY measurements may be used to systematically determine the cable type in the automatic mode. This cable type information may be used to perform diagnostics of the cable infrastructure or incorporated as part of a dynamic configuration or operational process.

Various aspects of the invention will become apparent to those skilled in the art upon review of the foregoing description. While various salient features of the invention are disclosed above, it will be apparent to those skilled in the art from this disclosure that the invention may be implemented or carried out in various ways, and thus the foregoing description should not be considered as excluding other embodiments. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

Claims (7)

1. A cable diagnostic system, comprising: a cable sensing component located in the physical layer for measuring electrical characteristics of an Ethernet cable connected to the physical layer;

a controller for determining a type of the Ethernet cable based on the measured electrical characteristic, the controller for generating a report of the determined Ethernet cable type;

wherein said measuring an electrical characteristic of an Ethernet cable coupled to said physical layer comprises measuring an insertion loss of said Ethernet cable;

wherein measuring the insertion loss of the ethernet cable means sending one, multiple or consecutive pulses with a predetermined frequency component into the cable, closing the link partner and disconnecting the cable pair from the line side or the opposite side of the transformer, and then measuring the attenuation magnitude and phase distortion of the retro-reflected incidental pulses at the transmitting end with the same polarity; the incidental pulse experiences an insertion loss corresponding to twice the length of the ethernet cable; alternatively, the first and second electrodes may be,

measuring the insertion loss of the ethernet cable refers to sending one, multiple or consecutive pulses with predetermined frequency components into the cable, closing the link partner and shortening the cable pair from the line side or the opposite side of the transformer, and then measuring the attenuation magnitude and phase distortion of the retro-reflected incidental pulses at the transmitting end with opposite polarity; the incidental pulse experiences an insertion loss corresponding to twice the length of the ethernet cable; alternatively, the first and second electrodes may be,

measuring the insertion loss of the ethernet cable means sending one, several or consecutive pulses with predetermined frequency components into the cable, closing the link partner and disconnecting and shortening the two cable pairs from the other pair on the line side or on the opposite side of the transformer to form a loop, and then measuring the attenuation magnitude and phase distortion of the retro-reflected incidental pulses at the transmitting end of the different pairs; the incidental pulse experiences an insertion loss corresponding to twice the length of the ethernet cable.

2. The cable diagnostic system of claim 1, wherein the cable detection assembly measures crosstalk of the ethernet cable.

3. The cable diagnostic system of claim 1, wherein the cable detection assembly measures a length of the ethernet cable.

4. An ethernet port configuration system, comprising:

a cable sensing component located in the physical layer for measuring electrical characteristics of an Ethernet cable connected to the physical layer;

a controller for determining the type of the Ethernet cable based on the measured electrical characteristic, the controller being operable to configure operation of an Ethernet port based on the determined Ethernet cable type;

wherein the cable detection component measures an insertion loss of the Ethernet cable;

wherein measuring the insertion loss of the ethernet cable means sending one, multiple or consecutive pulses with a predetermined frequency component into the cable, closing the link partner and disconnecting the cable pair from the line side or the opposite side of the transformer, and then measuring the attenuation magnitude and phase distortion of the retro-reflected incidental pulses at the transmitting end with the same polarity; the incidental pulse experiences an insertion loss corresponding to twice the length of the ethernet cable; alternatively, the first and second electrodes may be,

measuring the insertion loss of the ethernet cable refers to sending one, multiple or consecutive pulses with predetermined frequency components into the cable, closing the link partner and shortening the cable pair from the line side or the opposite side of the transformer, and then measuring the attenuation magnitude and phase distortion of the retro-reflected incidental pulses at the transmitting end with opposite polarity; the incidental pulse experiences an insertion loss corresponding to twice the length of the ethernet cable; alternatively, the first and second electrodes may be,

measuring the insertion loss of the ethernet cable means sending one, several or consecutive pulses with predetermined frequency components into the cable, closing the link partner and disconnecting and shortening the two cable pairs from the other pair on the line side or on the opposite side of the transformer to form a loop, and then measuring the attenuation magnitude and phase distortion of the retro-reflected incidental pulses at the transmitting end of the different pairs; the incidental pulse experiences an insertion loss corresponding to twice the length of the ethernet cable.

5. An Ethernet port configuration system according to claim 4, wherein said cable detection component measures crosstalk of said Ethernet cable.

6. An ethernet port configuration method, comprising:

upon initializing an ethernet port, determining a type of cable connected to the ethernet port based on the measured electrical characteristics; and

configuring the Ethernet port based on the determined cable type;

wherein the determining comprises measuring an insertion loss of the Ethernet cable;

wherein measuring the insertion loss of the ethernet cable means sending one, multiple or consecutive pulses with a predetermined frequency component into the cable, closing the link partner and disconnecting the cable pair from the line side or the opposite side of the transformer, and then measuring the attenuation magnitude and phase distortion of the retro-reflected incidental pulses at the transmitting end with the same polarity; the incidental pulse experiences an insertion loss corresponding to twice the length of the ethernet cable; alternatively, the first and second electrodes may be,

measuring the insertion loss of the ethernet cable refers to sending one, multiple or consecutive pulses with predetermined frequency components into the cable, closing the link partner and shortening the cable pair from the line side or the opposite side of the transformer, and then measuring the attenuation magnitude and phase distortion of the retro-reflected incidental pulses at the transmitting end with opposite polarity; the incidental pulse experiences an insertion loss corresponding to twice the length of the ethernet cable; alternatively, the first and second electrodes may be,

measuring the insertion loss of the ethernet cable means sending one, several or consecutive pulses with predetermined frequency components into the cable, closing the link partner and disconnecting and shortening the two cable pairs from the other pair on the line side or on the opposite side of the transformer to form a loop, and then measuring the attenuation magnitude and phase distortion of the retro-reflected incidental pulses at the transmitting end of the different pairs; the incidental pulse experiences an insertion loss corresponding to twice the length of the ethernet cable.

7. An Ethernet port configuration method according to claim 6, wherein said determining comprises measuring crosstalk of said Ethernet cable.