JP2546370B2 - Packet transfer characteristic measurement method - Google Patents
Packet transfer characteristic measurement methodInfo
- Publication number
- JP2546370B2 JP2546370B2 JP1117577A JP11757789A JP2546370B2 JP 2546370 B2 JP2546370 B2 JP 2546370B2 JP 1117577 A JP1117577 A JP 1117577A JP 11757789 A JP11757789 A JP 11757789A JP 2546370 B2 JP2546370 B2 JP 2546370B2
- Authority
- JP
- Japan
- Prior art keywords
- packet
- transmission
- packets
- measurement
- time
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Landscapes
- Data Exchanges In Wide-Area Networks (AREA)
Description
【発明の詳細な説明】 （産業上の利用分野） 本発明は、パケットを扱う系のパケット伝達特性を測
定する方法に関する。本発明は、特に、測定に使用する
パケットの一部に入力の順に通し番号を書き込み、出力
においてその通し番号を利用して伝達特性を測定する方
法に関する。The present invention relates to a method for measuring packet transfer characteristics of a system that handles packets. In particular, the present invention relates to a method of writing a serial number in a part of a packet used for measurement in the order of input and using the serial number at output to measure a transfer characteristic.
（従来の技術） パケットを扱う系におけるパケット伝達特性の一つで
ある伝達遅延時間分布の分散あるいは偏差の従来の測定
方式の第１の例を第３図に示す。符号１は測定用パケッ
ト送信装置（以下送信装置）、符号１−１は送信部、符
号１−４は送信時刻測定用時計あるいはカウンタ（以下
送信時計）、符号１−５は送信時刻記憶部、符号２は測
定用パケット受信装置（以下受信装置）、符号２−１は
受信部、符号２−７は１−４と同一の絶対時刻を示す到
着時刻測定用時計あるいはカウンタ（以下受信時計）、
符号３は被測定系を示す。(Prior Art) FIG. 3 shows a first example of a conventional measurement method of the dispersion or deviation of the transmission delay time distribution, which is one of the packet transmission characteristics in a system that handles packets. Reference numeral 1 is a measurement packet transmitter (hereinafter referred to as transmitter), reference numeral 1-1 is a transmitter, reference numeral 1-4 is a transmission time measurement clock or counter (hereinafter referred to as transmission clock), reference numeral 1-5 is a transmission time storage unit, Reference numeral 2 is a measuring packet receiving apparatus (hereinafter referred to as receiving apparatus), reference numeral 2-1 is a receiving unit, reference numeral 2-7 is an arrival time measuring clock or counter (hereinafter referred to as receiving clock) indicating the same absolute time as 1-4,
Reference numeral 3 indicates a system under measurement.
送信装置は、測定用パケットを１パケットのみ被測定
系に送信し、その送信時刻を送信時計１−４から読み取
り、送信時刻記憶１−５に記憶する。受信装置において
被測定系から出力される測定用パケットを受信した時刻
を受信時計２−７から読み取り、その時刻から送信時刻
記憶部１−５に記憶されている時刻を減算することによ
り伝達遅延時間が測定される。伝達遅延時間分布の分散
あるいは偏差は、この伝達遅延時間測定を多数回行い、
そのデータから計算される。すなわち、伝達遅延時間デ
ータをTi（ｉ＝１〜ｎ）とすると、伝達遅延時間分布の
分散は式（１）により計算される。また、偏差は分散の
平方根として計算される。The transmitter transmits only one packet for measurement to the system under measurement, reads the transmission time from the transmission clock 1-4, and stores it in the transmission time memory 1-5. The transmission delay time is obtained by reading the time when the measurement packet output from the measured system is received by the receiving device from the reception clock 2-7 and subtracting the time stored in the transmission time storage unit 1-5 from the time. Is measured. For the dispersion or deviation of the transmission delay time distribution, this transmission delay time measurement is performed many times,
Calculated from that data. That is, assuming that the transmission delay time data is T i (i = 1 to n), the dispersion of the transmission delay time distribution is calculated by the equation (1). Also, the deviation is calculated as the square root of the variance.
伝達遅延時間分布の分散あるいは偏差の測定方式の第
２の例を第４図に示す。符号１−６は送信時計１−４か
ら読み取った送信時刻を測定用パケットと一部に書き込
む送信時刻書き込み部、符号２−３は受信パケット数計
数器、符号２−８は受信した測定用パケットから送信時
刻書き込み部１−６で書き込まれた送信時刻を読み取る
送信時刻読み出し部を示す。 FIG. 4 shows a second example of the method of measuring the dispersion or deviation of the transmission delay time distribution. Reference numeral 1-6 is a transmission time writing unit that partially writes the transmission time read from the transmission clock 1-4 and the measurement packet, reference numeral 2-3 is a received packet counter, and reference numeral 2-8 is a received measurement packet. A transmission time reading unit for reading the transmission time written by the transmission time writing unit 1-6 is shown.
送信装置は、パケット送信時刻を送信時計１−４から
読み取り、その時刻を送信時刻書き込み部１−６におい
て測定用パケットに書き込み、被測定系にそのパケット
を送信する。伝達遅延時間分布の分散あるいは偏差は、
受信装置において被測定系から出力される測定用パケッ
トを受信した時刻を受信時計２−７から読み取り、その
時刻から送信時刻読み出し部２−８で測定用パケットか
ら読み出したパケット送信時刻を減算することにより測
定される伝達遅延時間を用いて計算される。すなわち、
受信パケット数計数器２−３のカウント値をｎとし、測
定された伝達遅延時間データをTi（ｉ＝１〜ｎ）とする
と、伝達遅延時間分布の分散は式（１）により計算され
る。また、偏差は分散の平方根として計算される。The transmission device reads the packet transmission time from the transmission clock 1-4, writes the time in the measurement packet in the transmission time writing unit 1-6, and transmits the packet to the measured system. The variance or deviation of the transmission delay time distribution is
The receiving device reads the time when the measurement packet output from the measured system is received from the reception clock 2-7, and subtracts the packet transmission time read from the measurement packet by the transmission time reading unit 2-8 from the time. Is calculated using the propagation delay time measured by That is,
Assuming that the count value of the received packet counter 2-3 is n and the measured transmission delay time data is T i (i = 1 to n), the variance of the transmission delay time distribution is calculated by the equation (1). . Also, the deviation is calculated as the square root of the variance.
パケットを扱う系におけるパケット伝達特性の一つで
あるパケット廃棄数の従来の測定方式の例を第５図に示
す。符号１−７は送信パケット数計数器を示す。FIG. 5 shows an example of a conventional method of measuring the number of discarded packets, which is one of the packet transfer characteristics in a system that handles packets. Reference numeral 1-7 indicates a transmitted packet number counter.
送信装置は、測定用パケットを被測定系に送信し、そ
の送信したパケット数を送信パケット数計数器１−７で
カウントする。受信装置は、受信した測定用パケット数
を受信パケット数計数器２−３でカウントする。パケッ
ト廃棄数は送信パケット数計数器１−７のカウント値か
ら受信パケット数計数器２−３のカウント値を減算する
ことにより測定される。The transmitting device transmits the measurement packet to the system under measurement, and the transmitted packet number counter 1-7 counts the transmitted packet number. The receiving device counts the number of received measurement packets with the received packet number counter 2-3. The number of dropped packets is measured by subtracting the count value of the received packet counter 2-3 from the count value of the transmitted packet counter 1-7.
（発明が解決しようとする課題） 上述した従来のパケット伝達特性測定方式では、
（１）伝達遅延時間分布の分散あるいは偏差の測定にお
いて送信時計と受信時計の絶対時刻を一致させる必要が
あり、特に送信装置と受信装置が離れて位置する場合に
実現が困難であるという欠点があった。また、（２）パ
ケット廃棄数の測定において、送信装置及び受信装置双
方のパケット数計数器の値を知る必要があるという欠点
があった。また、被測定系へのパケットの入力順序と被
測定系からのパケットの出力順序が同一の場合でも、被
測定系内にパケットが残留している可能性があり、送信
を停止した後その残留パケットが全て受信装置に到達す
るのに十分な時間待った後でなければ、パケットが廃棄
されたのか被測定系内に残留しているのか判断できない
ため、正確なパケット廃棄数は測定できないという欠点
があった。更に、測定時間全体にわたる総パケット廃棄
数しか測定できず、測定時間内のどの時点でパケット廃
棄が起きたか特定できないという欠点があった。(Problems to be Solved by the Invention) In the above-mentioned conventional packet transfer characteristic measuring method,
(1) In measuring the dispersion or deviation of the transmission delay time distribution, it is necessary to match the absolute times of the transmission clock and the reception clock, which is difficult to realize especially when the transmission device and the reception device are located apart from each other. there were. In addition, (2) there is a drawback that it is necessary to know the values of the packet number counters of both the transmitting device and the receiving device in the measurement of the number of discarded packets. Even if the order of inputting packets to the system under test and the order of outputting packets from the system under test are the same, packets may remain in the system under test. Only after waiting a sufficient amount of time for all packets to reach the receiving device, it is impossible to determine whether the packets have been discarded or remain in the system under measurement. there were. Further, there is a drawback that only the total number of dropped packets can be measured over the entire measurement time, and it is not possible to specify at which point in the measurement time the packet drop occurred.
本発明は、測定用パケットの一部に送信順の通し番号
を書き込み、受信装置においてその番号を利用すること
により上述した問題点を解決することを目的とする。An object of the present invention is to solve the above-mentioned problems by writing a serial number in the transmission order in a part of a measurement packet and using the serial number in a receiving device.
（課題を解決するための手段） 上記目的を達成するために、本発明は、情報をパケッ
ト単位で扱い被測定系の入力から出力へのパケット伝達
特性を測定する方法において、被測定系に等時間間隔に
パケットを入力すると共に入力されるパケットに入力順
の通し番号を書き込み、被測定系の出力側でパケットの
通し番号及び前記等時間間隔により被測定系でのパケッ
トの伝達遅延時間の分散を測定することに特徴がある。(Means for Solving the Problem) In order to achieve the above object, the present invention provides a method for measuring packet transfer characteristics from an input to an output of a system under test in which information is handled in units of packets. Input the packet at the time interval and write the serial number in the input order to the input packet, and measure the distribution of the packet transmission delay time in the measured system by the serial number of the packet and the equal time interval at the output side of the measured system. There is a feature in doing it.
（作用） 本発明では、測定用パケットの一部に送信順に通し番
号を書き込み被測定系に測定用パケットを送信するた
め、受信装置において受信したパケットの相対関係を知
ることができ、受信装置単独で伝達遅延時間分布の分散
あるいは偏差及びパケット廃棄数の測定を実現できる。(Operation) In the present invention, since serial numbers are written in a part of the measurement packets in the order of transmission and the measurement packets are transmitted to the system under measurement, it is possible to know the relative relationship of the packets received by the receiving device, and the receiving device alone. It is possible to measure the variance or deviation of the transmission delay time distribution and the number of dropped packets.
（実施例） 以下図面を参照して本発明の実施例を説明する。Embodiment An embodiment of the present invention will be described below with reference to the drawings.
第１図は、本発明の第一実施例であるパケット伝達遅
延時間分布の分散あるいは偏差の測定法を説明する図で
ある。FIG. 1 is a diagram for explaining a method of measuring the variance or deviation of the packet transmission delay time distribution, which is the first embodiment of the present invention.
符号１−２は通し番号書き込み部、符号１−３は等時
間間隔送信トリガ発生部、符号２−２は通し番号読み出
し部、符号２−４は到着時刻測定用時計あるいはカウン
タ、符号２−５は通し番号及び到着時刻記憶部を示す。Reference numeral 1-2 is a serial number writing section, reference numeral 1-3 is an equal time interval transmission trigger generating section, reference numeral 2-2 is a serial number reading section, reference numeral 2-4 is an arrival time measuring clock or counter, and reference numerals 2-5 are serial numbers. And an arrival time storage unit.
本第一実施例は従来の絶対時刻を利用した伝達遅延時
間分布の分散あるいは偏差の測定と異なり、送信装置に
おいて送信順に通し番号をパケットに書き込むことによ
り、受信装置のみにおいて受信した測定用パケットの相
対関係（到着時刻間隔）から伝達遅延時間分布の分散あ
るいは偏差を測定することを可能としたことに特徴があ
る。In the first embodiment, unlike the conventional method of measuring the dispersion or deviation of the transmission delay time distribution using absolute time, the serial number is written in the packet in the transmission order in the transmitting device, so that the relative number of the measurement packet received only in the receiving device. It is characterized in that it is possible to measure the variance or deviation of the transmission delay time distribution from the relationship (arrival time interval).
本第一実施例では、送信装置は、到着時刻測定用時計
あるいはカウンタ２−４の動作クロックと同期した同一
周波数のクロックにより時間間隔を決定する等時間間隔
送信トリガ発生部１−３からのトリガにより、通し番号
書き込み部１−２によって送信順に通し番号を書き込ま
れた測定用パケットを被測定系に送信する。受信装置
は、被測定系から出力される測定用パケットを受信し、
到着時刻測定用時計あるいはカウンタ２−４でその到着
時刻を測定すると共に通し番号読み出し部２−２により
受信した測定用パケットの通し番号を読み取り、双方を
記憶部２−５に記憶する。また、受信パケット数を受信
パケット数計数器２−３でカウントする。伝達遅延時間
分布の分散は、記憶部２−５に記憶された通し番号及び
到着時刻をそれぞれai,aj及びbi,bj（i,j＝１〜ｎ）と
し、等時間間隔送信トリガのトリガ間隔をτとすると式
（２）によって測定される。また、偏差は分散の平方根
として計算される。In the first embodiment, the transmission device uses the arrival time measurement clock or the equal time interval transmission trigger generator 1-3 for determining the time interval by the clock of the same frequency synchronized with the operation clock of the counter 2-4. Thus, the measurement packet in which the serial numbers are written in the transmission order by the serial number writing unit 1-2 is transmitted to the system under measurement. The receiving device receives the measurement packet output from the system under measurement,
The arrival time measuring clock or counter 2-4 measures the arrival time, the serial number of the received measurement packet is read by the serial number reading unit 2-2, and both are stored in the storage unit 2-5. Further, the number of received packets is counted by the received packet number counter 2-3. The distribution of the transmission delay time distribution is calculated by setting the serial numbers and the arrival times stored in the storage unit 2-5 to a i , a j and b i , b j (i, j = 1 to n), respectively, and transmitting them at equal time intervals. When the trigger interval of is τ, it is measured by the equation (2). Also, the deviation is calculated as the square root of the variance.
第２図は、本発明の第二実施例であるパケット廃棄数
測定法を説明する図である。 FIG. 2 is a diagram for explaining a packet discard number measuring method according to the second embodiment of the present invention.
符号２−６は受信した測定用パケットの通し番号記憶
部である。Reference numeral 2-6 is a serial number storage unit for the received measurement packet.
本第二実施例は従来のパケット廃棄数測定法と異な
り、送信装置において送信順に通し番号をパケットに書
き込むことにより、受信装置のみにおいて受信したパケ
ットの通し番号の欠落からパケット廃棄数の測定を可能
としたことに特徴がある。Unlike the conventional method of measuring the number of discarded packets, the second embodiment writes the serial numbers to the packets in the order of transmission in the transmitting device, thereby making it possible to measure the number of discarded packets from the lack of the serial number of the packet received only by the receiving device. It is characterized by this.
本第二実施例では、送信装置は通し番号書き込み部１
−２によって送信順に通し番号を書き込まれた測定用パ
ケットを被測定系に送信する。受信装置は被測定系から
出力される測定用パケットを受信し、その通し番号を通
し番号読み出し部２−２で読み取り、通し番号記憶部２
−６に記憶する。パケット廃棄数は、（１）被測定系へ
のパケットの入力順序と被測定系からのパケットの出力
順序が同一の場合は、受信した測定用パケットの通し番
号から前回受信した測定用パケットの通し番号を減算す
ることによりこれら二つのパケットを受信する間に廃棄
されたパケット数を測定することができる。従って、測
定時間全体にわたる総パケット廃棄数とともに到着時刻
間隔の分解能で廃棄の生じた時刻を特定することができ
る。（２）被測定系へのパケットの入力順序と被測定系
からのパケットの出力順序が異なる場合は、送信を停止
した後被測定系内に残留しているパケットが受信装置に
全て到着するのに十分な時間だけ受信を継続した後、記
憶部２−６に記憶された通し番号を検査し、通し番号の
欠落数を数えることにより送信パケット数を知らなくて
も廃棄数を測定することができる。In the second embodiment, the transmitter is the serial number writing unit 1
The measurement packet in which the serial number is written in the transmission order by -2 is transmitted to the measured system. The receiving device receives the measurement packet output from the system under measurement, reads the serial number by the serial number reading unit 2-2, and outputs the serial number storage unit 2
Store in -6. The packet discard number is (1) the serial number of the previously received measurement packet from the serial number of the received measurement packet if the packet input order to the measured system and the packet output order from the measured system are the same. By subtracting, it is possible to measure the number of packets discarded while receiving these two packets. Therefore, it is possible to specify the time at which the packet was discarded with the resolution of the arrival time interval together with the total number of discarded packets over the entire measurement time. (2) If the packet input order to the DUT and the packet output order from the DUT are different, all packets remaining in the DUT after the transmission is stopped will arrive at the receiving device. After continuing reception for a sufficient time, the serial number stored in the storage unit 2-6 is inspected, and the number of dropped packets can be measured without counting the number of transmitted packets by counting the number of missing serial numbers.
（発明の効果） 以上説明したように、本発明は送信装置において測定
用パケットに送信順に通し番号を書き込むことにより、
送受信装置間で困難な絶対時刻の一致を必要としないで
パケット伝達遅延時間分布の分散あるいは偏差を測定で
きる効果がある。また、パケットの入力順序と出力順序
が同一の被測定系において、到着時刻間隔の分解能で廃
棄の生じた時刻を特定することができる効果がある。ま
た、パケットの入力順序と出力順序が異なる被測定系に
おいて、送信パケット数を知らなくても受信装置側のみ
でパケット廃棄数を測定できる効果がある。(Effect of the Invention) As described above, according to the present invention, the serial number is written in the measurement packet in the transmission order in the transmission device.
There is an effect that the dispersion or deviation of the packet transmission delay time distribution can be measured without requiring difficult coincidence of absolute times between the transmitting and receiving devices. In addition, in the measured system in which the packet input order and the packet output order are the same, it is possible to specify the time when the discard occurs with the resolution of the arrival time interval. In addition, in the measured system in which the packet input order and the packet output order are different, the number of discarded packets can be measured only by the receiving device side without knowing the number of transmitted packets.
第１図は本発明の第一実施例を示す図、 第２図は本発明の第二実施例を示す図、 第３図は従来のパケット伝達遅延時間分布の分散あるい
は偏差の測定方式の第一例を示す図、 第４図は従来のパケット伝達遅延時間分布の分散あるい
は偏差の測定方式の第二例を示す図、 第５図は従来のパケット廃棄数測定方式を示す図であ
る。 1:測定用パケット送信装置、 １−1:送信部、 １−2:通し番号書き込み部、 １−3:等時間間隔送信トリガ発生部、 １−4:送信時刻測定用時計あるいはカウンタ、 １−5:送信時刻記憶部、 １−6:送信時刻書き込み部、 １−7:送信パケット数計数器、 2:測定用パケット受信装置、 ２−1:受信部、 ２−2:通し番号読み出し部、 ２−3:受信パケット数計数器、 ２−4:到着時刻測定用時計あるいはカウンタ、 ２−5:通し番号及び到着時刻記憶部、 ２−6:通し番号記憶部、 ２−7:1−４と同一の絶対時刻を示す到着時刻測定用時
計あるいはカウンタ、 ２−8:送信時刻読み出し部、 3:被測定系。FIG. 1 is a diagram showing a first embodiment of the present invention, FIG. 2 is a diagram showing a second embodiment of the present invention, and FIG. 3 is a diagram showing a conventional method for measuring dispersion or deviation of packet transmission delay time distribution. FIG. 4 is a diagram showing an example, FIG. 4 is a diagram showing a second example of the conventional method of measuring the dispersion or deviation of the packet transmission delay time distribution, and FIG. 5 is a diagram showing the conventional packet discard number measuring method. 1: Measurement packet transmission device, 1-1: Transmission unit, 1-2: Serial number writing unit, 1-3: Equal time interval transmission trigger generation unit, 1-4: Transmission time measurement clock or counter, 1-5 : Transmission time storage unit, 1-6: Transmission time writing unit, 1-7: Transmission packet number counter, 2: Measurement packet receiver, 2-1: Reception unit, 2-2: Serial number reading unit, 2- 3: Received packet counter, 2-4: Arrival time measurement clock or counter, 2-5: Serial number and arrival time storage unit, 2-6: Serial number storage unit, 2-7: Same absolute as 4 Arrival time measurement clock or counter that indicates the time, 2-8: Transmission time reading unit, 3: System under test.
Claims (2)
から出力へのパケット伝達特性を測定する方法におい
て、 被測定系に等時間間隔にパケットを入力すると共に入力
されるパケットに入力順の通し番号を書き込み、 被測定系の出力側でパケットの通し番号及び前記等時間
間隔により被測定系でのパケットの伝達遅延時間の分散
を測定することを特徴とするパケット伝達特性測定方
法。1. A method for handling information in units of packets and measuring a packet transfer characteristic from an input to an output of a measured system, wherein packets are input to the measured system at equal time intervals and input packets are input in the input order. A method for measuring packet transfer characteristics, characterized in that a serial number is written and the packet transmission delay time dispersion in the measured system is measured on the output side of the measured system based on the packet serial number and the equal time interval.
記分散を、 （ｎは正の整数、i,j＝１〜n,ai,ajは通し番号、bi,bj
は到着時刻、τは等時間間隔）により測定する請求項１
記載のパケット伝達特性測定方法。2. The dispersion of packet transmission delay time in the system under test is (N is a positive integer, i, j = 1 to n, a i , a j are serial numbers, b i , b j
Is the arrival time and τ is an equal time interval).
The packet transfer characteristic measuring method described.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1117577A JP2546370B2 (en) | 1989-05-12 | 1989-05-12 | Packet transfer characteristic measurement method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1117577A JP2546370B2 (en) | 1989-05-12 | 1989-05-12 | Packet transfer characteristic measurement method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02299343A JPH02299343A (en) | 1990-12-11 |
| JP2546370B2 true JP2546370B2 (en) | 1996-10-23 |
Family
ID=14715265
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1117577A Expired - Lifetime JP2546370B2 (en) | 1989-05-12 | 1989-05-12 | Packet transfer characteristic measurement method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2546370B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07154397A (en) * | 1993-11-26 | 1995-06-16 | Nec Corp | Method and device for reducing cell abandonment |
| JP3569371B2 (en) * | 1996-01-24 | 2004-09-22 | 富士通株式会社 | Repeater test system and test method |
| WO2008117379A1 (en) | 2007-03-23 | 2008-10-02 | Fujitsu Limited | Method for measuring transmission quality of packet, device for measuring transmission of packet, and device for measuring reception of packet |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6086667A (en) * | 1983-10-18 | 1985-05-16 | Fujitsu Ltd | Sequential number management system |
| JPS61224640A (en) * | 1985-03-29 | 1986-10-06 | Hitachi Ltd | Data block transfer system |
| JPS61260738A (en) * | 1985-05-15 | 1986-11-18 | Hitachi Ltd | Multile address communication service system |
| JPS62264798A (en) * | 1986-05-13 | 1987-11-17 | Nec Corp | Time switch |
-
1989
- 1989-05-12 JP JP1117577A patent/JP2546370B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH02299343A (en) | 1990-12-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5477531A (en) | Method and apparatus for testing a packet-based network | |
| US5521907A (en) | Method and apparatus for non-intrusive measurement of round trip delay in communications networks | |
| EP1109360B1 (en) | ATM test equipment operable as source and responder for conducting multiple tests | |
| US6741952B2 (en) | Instrument timing using synchronized clocks | |
| US20020006115A1 (en) | Non-deterministic software delay estimation method and system for packet based data network systems | |
| EP0082535B1 (en) | Unwanted signal detecting and measuring apparatus | |
| US7058020B2 (en) | Hardware time stamping and registration of packetized data method and system | |
| WO1999025085B1 (en) | Method and apparatus for performing service level analysis of communications network performance metrics | |
| CN104144088A (en) | Network delay measuring method with delay measuring accuracy improved | |
| JPH022971A (en) | Logical analyzer | |
| US6122257A (en) | Method for collecting information about physical constitution of lan system, method of specifying collision terminals, and method for detecting noise-generated position | |
| KR900019424A (en) | Apparatus and method for coupling a digital signal to a communication medium in the form of a packet | |
| WO1992022967A1 (en) | Method and apparatus for testing a packet-based network | |
| JP2546370B2 (en) | Packet transfer characteristic measurement method | |
| EP0381878B1 (en) | Network diagnosis apparatus and method | |
| EP0660938B1 (en) | Full and partial cycle counting apparatus and method | |
| JP2640985B2 (en) | Packet delay measurement device | |
| CN110244253A (en) | Provincial measurement centre's standard volume passes online management-control method | |
| JP2024051700A (en) | Measurement device, measurement method, and program | |
| JPH0358543A (en) | Packet composing device | |
| RU2233554C1 (en) | Device for metering length of two-wire data transfer line | |
| JP2559237Y2 (en) | Serial data sampling signal generator | |
| JP2023074863A (en) | data collection device | |
| JP2576975B2 (en) | Bit error distribution measuring device | |
| JPH04321348A (en) | Transmission delay measurement device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20070808 Year of fee payment: 11 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20080808 Year of fee payment: 12 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20080808 Year of fee payment: 12 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090808 Year of fee payment: 13 |
|
| EXPY | Cancellation because of completion of term | ||
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090808 Year of fee payment: 13 |