Source: http://www.google.com/patents/US20090262645?ie=ISO-8859-1
Timestamp: 2014-09-20 12:03:08
Document Index: 77506610

Matched Legal Cases: ['art 105', 'art 105', 'art 107', 'art 105', 'art 106', 'art 106']

Patent US20090262645 - Method and equipment for shaping transmission speed of data traffic flow - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign in<nobr>Advanced Patent Search</nobr>PatentsA method and apparatus for monitoring and limiting the transmission speed of a data traffic flow in a situation where the traffic flow also includes delay-critical traffic. With the sending of each protocol data unit it is determined whether the sending of the next protocol data unit should be delayed...http://www.google.com/patents/US20090262645?utm_source=gb-gplus-sharePatent US20090262645 - Method and equipment for shaping transmission speed of data traffic flowAdvanced Patent SearchPublication numberUS20090262645 A1Publication typeApplicationApplication numberUS 12/427,938Publication dateOct 22, 2009Filing dateApr 22, 2009Priority dateApr 22, 2008Also published asCN101567851A, CN101567851B, EP2112791A1, US8139481Publication number12427938, 427938, US 2009/0262645 A1, US 2009/262645 A1, US 20090262645 A1, US 20090262645A1, US 2009262645 A1, US 2009262645A1, US-A1-20090262645, US-A1-2009262645, US2009/0262645A1, US2009/262645A1, US20090262645 A1, US20090262645A1, US2009262645 A1, US2009262645A1InventorsMikko LaulainenOriginal AssigneeTellabs Oy Et Al.Export CitationBiBTeX, EndNote, RefManReferenced by (2), Classifications (14), Legal Events (1) External Links: USPTO, USPTO Assignment, EspacenetMethod and equipment for shaping transmission speed of data traffic flowUS 20090262645 A1Abstract A method and apparatus for monitoring and limiting the transmission speed of a data traffic flow in a situation where the traffic flow also includes delay-critical traffic. With the sending of each protocol data unit it is determined whether the sending of the next protocol data unit should be delayed in order to meet a condition set on the transmission speed. It is also determined whether the transfer speed of delay-critical traffic meets a preset condition. If the transfer speed meets the condition, delay-critical protocol data units will not be delayed but if the condition is not met, delay-critical protocol data units will be delayed just like non-delay-critical protocol data units. Thus the transfer speed of non-delay-critical traffic adapts to variations in the transfer speed of delay-critical traffic and, furthermore, the transmission speed of the traffic flow can be monitored and limited.
a) determine, in response to sending of a protocol data unit, whether sending of a next protocol data unit should be delayed in order to meet a condition set on the transmission speed, b) delay the sending of the next protocol data unit in response to a situation in which the next protocol data unit belongs to a first traffic category and the sending of the next protocol data unit should be delayed in order to meet the condition set on the transmission speed, c) determine whether transfer speed of protocol data units belonging to a second traffic category and constituting part of the traffic flow meets a preset condition, d) allow the sending of the next protocol data unit in response to a situation in which the next protocol data unit belongs to the second traffic category and the transfer speed meets the preset condition, even if the sending of the next protocol data unit should be delayed in order to meet the condition set on the transmission speed, and e) delay the sending of the next protocol data unit in response to a situation in which the next protocol data unit belongs to the second traffic category and the sending of the next protocol data unit should be delayed in order to meet the condition set on the transmission speed and the transfer speed does not meet the preset condition. 2. An equipment according to claim 1, wherein the transfer speed is speed of arrival of traffic representing the second traffic category and constituting a part of the data traffic flow, and the control equipment is arranged to determine whether the speed of arrival meets the preset condition.
T_next=T � tx+PKS/S � tx where T_tx is a sending moment of a starting point of the protocol data unit, PKS is the size of the protocol data unit, S_tx is a maximum permissible transmission speed of the data traffic flow, and T_next is the earliest moment of time at which the next protocol data unit can be sent without exceeding the maximum permissible transmission speed. 7. An equipment according to claim 1, wherein the control equipment is arranged to:
decrease a CIR (Committed Information Rate) transmission quota by an amount corresponding to the size of the protocol data unit in response to the sending of the protocol data unit, increase the CIR transmission quota by an amount corresponding to the maximum permissible mean value of the transmission speed, and determine whether the sending of the next protocol data unit should be delayed in order to meet the condition set on the transmission speed, by comparing a momentary value of the CIR transmission quota to a predetermined threshold value. 8. An equipment according to claim 7, wherein the control equipment is arranged to:
decrease a PIR (Peak Information Rate) transmission quota by an amount corresponding to the size of the protocol data unit in response to the sending of the protocol data unit, increase the PIR transmission quota by an amount corresponding to the highest permissible maximum value of the transmission speed, and determine whether the sending of the next protocol data unit should be delayed in order to meet the condition set on the transmission speed, by comparing a momentary value of the PIR transmission quota to a second predetermined threshold value. 9. An equipment according to claim 2, wherein the control equipment is arranged to determine whether the speed of arrival meets the preset condition based on equation
T=T � rx+PKS/S � rx where T_rx is a moment of arrival of a starting point of a last-arrived protocol data unit belonging to the second traffic category, PKS is the size of the last-arrived protocol data unit, S_rx is the maximum permissible value of the speed of arrival, and T is a moment of time earlier to which the value of the speed of arrival exceeds the maximum permissible value and later to which the value of the speed of arrival remains below the maximum permissible value. 10. An equipment according to claim 2, wherein the control equipment is arranged to:
decrease a CIR reception quota by an amount corresponding to the size of a protocol data unit belonging to the second traffic category in response to the reception of the protocol data unit, increase the CIR reception quota by an amount corresponding to the maximum permissible mean value of the speed of arrival, and determine whether the speed of arrival meets the preset condition by comparing a momentary value of the CIR reception quota to a predetermined threshold value. 11. An equipment according to claim 4, wherein the control equipment is arranged to:
decrease a PIR reception quota by an amount corresponding to the size of a protocol data unit belonging to the second traffic category in response to the reception of the protocol data unit, increase the PIR reception quota by an amount corresponding to the highest permissible maximum value of the speed of arrival, and determine whether the speed of arrival meets the second preset condition by comparing a momentary value of the PIR reception quota to a second predetermined threshold value. 12. An equipment according to claim 10, wherein the control equipment is arranged to increase the CIR reception quota by an amount corresponding to the maximum permissible mean value of the speed of arrival in response to at least one of the following events: reception of a protocol data unit, transmission of a protocol data unit, the current time reaching one of predetermined update moments of time.
decrease a CIR_B transmission quota by an amount corresponding to the size of a protocol data unit belonging to the second traffic category in response to the sending of the protocol data unit, increase the CIR_B transmission quota by an amount corresponding to the maximum permissible mean value of the transmission speed of traffic representing the second traffic category, and determine whether the transmission speed of traffic representing the second traffic category meets the preset condition by comparing a momentary value of the CIR_B transmission quota to a predetermined threshold value. 15. An equipment according to claim 1, wherein the protocol data units comprise one of the following alternatives: IP (Internet Protocol) packets, ATM (Asynchronous Transfer Mode) cells, Ethernet units, Frame Relay units, and MPLS (Multiprotocol Label Switching) units.
a) determine, in response to sending of a protocol data unit, whether sending of a next protocol data unit should be delayed in order to meet a condition set on transmission speed of the data traffic flow, b) delay the sending of the next protocol data unit in response to a situation in which the next protocol data unit belongs to a first traffic category and the sending of the next protocol data unit should be delayed in order to meet the condition set on the transmission speed, c) determine whether transfer speed of protocol data units belonging to a second traffic category and constituting part of the traffic flow meets a preset condition, d) allow the sending of the next protocol data unit in response to a situation in which the next protocol data unit belongs to the second traffic category and the transfer speed meets the preset condition, even if the sending of the next protocol data unit should be delayed in order to meet the condition set on the transmission speed, and e) delay the sending of the next protocol data unit in response to a situation in which the next protocol data unit belongs to the second traffic category and the sending of the next protocol data unit should be delayed in order to meet the condition set on the transmission speed and the transfer speed does not meet the preset condition. 17. A network element according to claim 16, wherein the network element is at least one of the following: an IP (Internet Protocol) router, Ethernet switch, ATM (Asynchronous Transfer Mode) switch, base station of a mobile communications network, and an MPLS (Multi Protocol Label Switching) switch.
a) determining, in response to sending of a protocol data unit, whether sending of a next protocol data unit should be delayed in order to meet a condition set on the transmission speed, b) delaying the sending of the next protocol data unit in response to a situation in which the next protocol data unit belongs to a first traffic category and the sending of the next protocol data unit should be delayed in order to meet the condition set on the transmission speed, c) determining whether transfer speed of protocol data units belonging to a second traffic category and constituting part of the traffic flow meets a preset condition, d) allowing the sending of the next protocol data unit in response to a situation in which the next protocol data unit belongs to the second traffic category and the transfer speed meets the preset condition, even if the sending of the next protocol data unit should be delayed in order to meet the condition set on the transmission speed, and e) delaying the sending of the next protocol data unit in response to a situation in which the next protocol data unit belongs to the second traffic category and the sending of the next protocol data unit should be delayed in order to meet the condition set on the transmission speed and the transfer speed does not meet the preset condition. 19. A method according to claim 18, wherein the transfer speed is speed of arrival of traffic which represents the second traffic category and which constitutes part of the data traffic flow, and the method comprises determining whether the speed of arrival meets the preset condition.
T_next=T � tx+PKS/S � tx where T_tx is a sending moment of a starting point of the protocol data unit, PKS is the size of the protocol data unit, S_tx is a maximum permissible transmission speed of the data traffic flow, and T_next is the earliest moment of time at which the next protocol data unit can be sent without exceeding the maximum permissible transmission speed. 24. A method according to claim 18, wherein the method comprises:
decreasing a CIR (Committed Information Rate) transmission quota by an amount corresponding to the size of the protocol data unit in response to the sending of the protocol data unit, increasing the CIR transmission quota by an amount corresponding to the maximum permissible mean value of the transmission speed, and determining whether the sending of the next protocol data unit should be delayed in order to meet the condition set on the transmission speed, by comparing a momentary value of the CIR transmission quota to a predetermined threshold value. 25. A method according to claim 24, wherein the method comprises:
decreasing a PIR (Peak Information Rate) transmission quota by an amount corresponding to the size of the protocol data unit in response to the sending of the protocol data unit, increasing the PIR transmission quota by an amount corresponding to the highest permissible maximum value of the transmission speed, and determining whether the sending of the next protocol data unit should be delayed in order to meet the condition set on the transmission speed, by comparing a momentary value of the PIR transmission quota to a second predetermined threshold value. 26. A method according to claim 19, wherein the method comprises determining whether the speed of arrival meets the preset condition, based on equation
T=T � rx+PKS/S � rx where T_rx is a moment of arrival of a starting point of a last-arrived protocol data unit belonging to the second traffic category, PKS is the size of the last-arrived protocol data unit, S_rx is a maximum permissible value of the speed of arrival, and T is the moment of time earlier to which the value of the speed of arrival exceeds the maximum permissible value and later to which the value of the speed of arrival remains below the maximum permissible value. 27. A method according to claim 19, wherein the method comprises:
decreasing a CIR reception quota by an amount corresponding to the size of a protocol data unit belonging to the second traffic category in response to the reception of the protocol data unit, increasing the CIR reception quota by an amount corresponding to the maximum permissible mean value of the speed of arrival, and determining whether the speed of arrival meets the preset condition by comparing a momentary value of the CIR reception quota to a predetermined threshold value. 28. A method according to claim 21, wherein the method comprises:
decreasing a PIR reception quota by an amount corresponding to the size of a protocol data unit belonging to the second traffic category in response to the reception of the protocol data unit, increasing the PIR reception quota by an amount corresponding to the highest permissible maximum value of the speed of arrival, and determining whether the speed of arrival meets the second preset condition by comparing a momentary value of the PIR reception quota to a second predetermined threshold value. 29. A method according to claim 27, wherein the CIR reception quota is increased by an amount corresponding to the maximum permissible mean value of the speed of arrival in response to at least one of the following events: reception of a protocol data unit, transmission of a protocol data unit, the current time reaching one of predetermined update moments of time.
decreasing a CIR_B transmission quota by an amount corresponding to the size of a protocol data unit belonging to the second traffic category in response to the sending of the protocol data unit, increasing the CIR_B transmission quota by an amount corresponding to the maximum permissible mean value of the transmission speed of traffic representing the second traffic category, and determining whether the transmission speed of traffic representing the second traffic category meets the preset condition by comparing a momentary value of the CIR_B transmission quota to a predetermined threshold value. 32. A method according to claim 18, wherein the protocol data units comprise one of the following alternatives: IP (Internet Protocol) packets, ATM (Asynchronous Transfer Mode) cells, Ethernet units, MPLS (Multiprotocol Label Switching) units, and Frame Relay units.
a) determine, in response to sending of a protocol data unit, whether sending of the next protocol data unit should be delayed in order to meet a condition set on the transmission speed, b) delay the sending of the next protocol data unit in response to a situation in which the next protocol data unit belongs to a first traffic category and the sending of the next protocol data unit should be delayed in order to meet the condition set on the transmission speed, c) determine whether transfer speed of protocol data units belonging to a second traffic category and constituting part of the traffic flow meets a preset condition, d) allow the sending of the next protocol data unit in response to a situation in which the next protocol data unit belongs to the second traffic category and the transfer speed meets the preset condition, even if the sending of the next protocol data unit should be delayed in order to meet the condition set on the transmission speed, and e) delay the sending of the next protocol data unit in response to a situation in which the next protocol data unit belongs to the second traffic category and the sending of the next protocol data unit should be delayed in order to meet the condition set on the transmission speed and the transfer speed does not meet the preset condition. Description
FIELD Embodiments of the invention relates to shaping the transmission speed of a data traffic flow. Some embodiments of the invention are directed to a method and equipment for shaping the transmission speed of a data traffic flow. Some embodiments of the invention are also directed to a network element and a computer program.
BACKGROUND In many communications applications it is advantageous and sometimes even necessary that protocol data units are defined to belong to different traffic categories such as Classes of Service (CoS) based on the requirements of the applications using the communications service and, on the other hand, on the Service Level Agreements (SLA), for example, between the service provider and the customers. Such protocol data units may be e.g. IP (Internet Protocol) packets, ATM (Asynchronous Transfer Mode) cells, Ethernet units, Frame Relay units, or MPLS (Multiprotocol Label Switching) units. For example, in a VoIP (Voice over Internet Protocol) telephony application it is important that the data transfer delay and delay variation remain below permitted limit values. Such permissible limit values can be defined in a service quality agreement, for instance. However, when downloading a web page, for example, the transfer delay and its variation are significantly less critical quantities.
The speed properties of a traffic flow typically are monitored and/or limited at a network element of a communications network, which network element is adapted to receive, buffer and forward protocol data units. The network element may be e.g. an IP (Internet Protocol) router, Ethernet switch, ATM (Asynchronous Transfer Mode) switch, base station of a mobile communications network, an MPLS (Multi Protocol Label Switching) switch, or a combination of these. The speed properties typically are monitored and/or limited by monitoring the arrival speeds of traffic flows arriving at the network element and/or by monitoring and/or shaping the transmission speeds of traffic flows departing from the network element. The operation in which the speed properties of a traffic flow are altered is referred to as �shaping�, and the equipment that does the shaping is referred to as a �shaper�.
SUMMARY Embodiments of the present invention are directed to a novel equipment for shaping the transmission speed of a data traffic flow in which each protocol data unit is arranged to belong to one of at least two traffic categories. The equipment includes a control equipment arranged to:
a) determine, in response to the sending of a protocol data unit, whether the sending of the next protocol data unit should be delayed in order to meet a condition set on the transmission speed, and b) delay the sending of the next protocol data unit in response to a situation in which the next protocol data unit belongs to a first traffic category and the sending of the next protocol data unit should be delayed in order to meet a condition set on the transmission speed, c) determine whether the transfer speed of protocol data units belonging to a second traffic category and constituting part of the traffic flow meets a preset condition, d) in response to a situation in which the next protocol data unit belongs to the second traffic category and the transfer speed meets the preset condition, allow the sending of the next protocol data unit even if the sending of the next protocol data unit should be delayed in order to meet the condition set on the transmission speed, and e) delay the sending of the next protocol data unit in response to a situation in which the next protocol data unit belongs to the second traffic category and the sending of the next protocol data unit should be delayed in order to meet a condition set on the transmission speed and the transfer speed does not meet the preset condition. The transfer speed of protocol data units belonging to the second traffic category may be the speed of arrival of traffic which represents the second traffic category and constitutes part of the traffic flow, or the transmission speed of the traffic. Momentary speed of arrival may differ from the momentary transmission speed as traffic typically is buffered between reception and transmission. In addition, speed of arrival and transmission speed will differ if protocol data units are discarded after reception.
a) it is determined, in response to the sending of a protocol data unit, whether the sending of the next protocol data unit should be delayed in order to meet a condition set on the transmission speed, and b) the sending of the next protocol data unit is delayed in response to a situation in which the next protocol data unit belongs to a first traffic category and the sending of the next protocol data unit should be delayed in order to meet a condition set on the transmission speed, c) it is determined whether the transfer speed of protocol data units belonging to a second traffic category and constituting part of the traffic flow meets a preset condition, d) the sending of the next protocol data unit is allowed in response to a situation in which the next protocol data unit belongs to the second traffic category and the transfer speed meets the preset condition, even if the sending of the next protocol data unit should be delayed in order to meet the condition set on the transmission speed, and e) the sending of the next protocol data unit is delayed in response to a situation in which the next protocol data unit belongs to the second traffic category and the sending of the next protocol data unit should be delayed in order to meet a condition set on the transmission speed and the transfer speed does not meet the preset condition. Embodiments of the invention are also directed to a novel computer program for controlling a programmable processor to shape the transmission speed of a data traffic flow in which each protocol data unit is arranged to belong to one of at least two traffic categories. The computer program includes instructions executable by a programmable processor for making the programmable processor:
a) determine, in response to the sending of a protocol data unit, whether the sending of the next protocol data unit should be delayed in order to meet a condition set on the transmission speed, and b) delay the sending of the next protocol data unit in response to a situation in which the next protocol data unit belongs to a first traffic category and the sending of the next protocol data unit should be delayed in order to meet a condition set on the transmission speed, c) determine whether the transfer speed of protocol data units belonging to a second traffic category and constituting part of the traffic flow meets a preset condition, d) allow the sending of the next protocol data unit in response to a situation in which the next protocol data unit belongs to the second traffic category and the transfer speed meets the preset condition, even if the sending of the next protocol data unit should be delayed in order to meet the condition set on the transmission speed, and e) delay the sending of the next protocol data unit in response to a situation in which the next protocol data unit belongs to the second traffic category and the sending of the next protocol data unit should be delayed in order to meet a condition set on the transmission speed and the transfer speed does not meet the preset condition. The various embodiments of the invention are characterised by that which is specified in the dependent claims.
BRIEF DESCRIPTION OF DRAWINGS Embodiments of the invention and their advantages will now be described in closer detail with reference to the embodiments presented as examples and to the accompanying Figures where:
DESCRIPTION OF EMBODIMENTS OF THE INVENTION FIG. 1 shows, in a block diagram, an equipment 101 according to an embodiment of the invention for shaping the transmission speed of a data traffic flow. Each protocol data unit (PDU) is arranged to belong to one of at least two traffic categories. The traffic categories may be Classes of Service (CoS), for instance. The protocol data units may be, for example, IP (Internet Protocol) packets, ATM (Asynchronous Transfer Mode) cells, Ethernet units, MPLS (Multiprotocol Label Switching) units, and/or Frame Relay units. The equipment 101 is connected with a system 108 which is arranged to receive, buffer, and send protocol data units. For illustrative purposes, the operation of the system 108 is briefly described before describing the equipment 101 according to an embodiment of the invention.
Functional part 105 is arranged to determine, based on a predetermined rule, in response to the sending of a protocol data unit, whether the sending of the next protocol data unit should be delayed in order to meet a condition set on the transmission speed of the traffic flow. The protocol data unit sent may belong to either one of the traffic categories A and B. In other words, the need for delay is determined regardless of which traffic category, A or B, the protocol data unit belongs to. The send moment of the protocol data unit can be defined to be the starting moment or the ending moment of transmission, for example. If the send moment is the starting moment of transmission, the phrase �protocol data unit sent� covers also a protocol data unit which is being sent at the moment. Functional part 105 is arranged to deliver to functional part 107 a piece of information 117 indicating the need for delay and advantageously also the end moment of the potential delay. Functional part 105 is arranged to receive from the system 108 a piece of information 115 on the basis of which it can be determined whether the sending of the next protocol data unit should be delayed in order to meet a condition set on the transmission speed of the traffic flow. The determining can be done in many different ways, so the piece of information 115 may contain different information in different embodiments of the invention. Ways of doing the determining are given as examples later in this document.
information 113=�1� if the next protocol data unit belongs to traffic category A, information 113=�0� if the next protocol data unit belongs to traffic category B, information 114=�1� indicates that sending of the next protocol data unit is not allowed, information 114=�0� indicates that sending of the next protocol data unit is allowed, information 117=�1� if there is a need for delay, information 117=�0� if there is no need for delay, information 118=�1� if the transfer speed of traffic representing traffic category B does not meet the condition set on it, and information 118=�0� if the transfer speed of traffic representing traffic category B meets the condition set on it. Information 114 can be produced using logic AND and OR operations as follows: Information 114=information 117 AND (information 113 OR information 118). The next protocol data unit may change during the delay, because during the delay the buffer memory 102 may receive a protocol data unit which according to the scheduling algorithm has a better right to become chosen than the protocol data unit which had been chosen as the next protocol data unit in the situation that prevailed at the beginning of delaying. Thus the piece of information 113 which indicates the traffic category of the next protocol data unit may change during the delaying. Therefore it is possible that during the delaying the piece of information 114 comes to indicate that the sending of the next protocol data unit will not be delayed, whereby the delaying will not be continued even if there were delaying time still left.
T_next=T � tx+PKS/S � tx (1)
whether the sending of the next protocol data unit should be delayed in order to meet the condition set on the transmission speed of the traffic flow. S_tx is the maximum permissible transmission speed [bit/s] of the traffic flow and T_next is the earliest moment of time at which the next protocol data unit can be sent without exceeding the maximum permissible transmission speed. If T_next is greater than current time t (T_next>t) the sending of the next protocol data unit should be delayed in order to meet the condition set on the transmission speed until t=T_next. The information 117 can be set e.g. as follows: information 117=�1� if current time t<T_next, and �0� if t≧T_next.
T_next=T_last� tx+PKS_next/S � tx−PKS_next/C � tx (2)
whether the sending of the next protocol data unit should be delayed in order to meet the condition set on the transmission speed of the traffic flow. C_tx is the transmission capacity [bit/s] which may be the capacity of the data transfer link out of the network element, for example. If T_next is greater than current time, the sending of the next protocol data unit should be delayed in order to meet the condition set on the transmission speed. The information 117 can be set e.g. as follows: information 117=�1� if current time t<T_next, and �0� if t≧T_next. Equation (1) has the advantage over equation (2) that when using equation (1) the T_next value need not be re-calculated in a situation where a protocol data unit with a higher priority is received at the buffer memory 102 during the delaying, i.e. in a situation where the next protocol data unit changes during the delaying.
VTS_CIR=max{T � tx−CBS� tx/CIR� tx,VTS_CIRprev}+PKS/CIR� tx (3)
VTS_PIR=max{T � tx,VTS_PIRprev}+PKS/PIR� tx, and (4)
whether the sending of the next protocol data unit should be delayed in order to meet the condition set on the transmission speed of the traffic flow. CIR_tx (Committed Information Rate) refers to the maximum permissible mean value of transmission speed [bit/s], CBS_tx (Committed Burst Size) refers to the burst size [bit] by which the maximum permissible mean value can be momentarily exceeded, PIR_tx (Peak Information Rate) refers to the highest permissible maximum value of the transmission speed [bit/s], and T_next refers to the earliest moment of time at which the next protocol data unit can be sent without violating the transmission speed limitations defined by CIR_tx, CBS_tx, and PIR_tx. VTS_CIR and VTS_PIR are auxiliary variables in which the subscript �prev� refers to the previous values of the respective auxiliary variables. The information 117 can be set e.g. as follows: information 117=�1� if current time t<T_next, and �0� if t≧T_next.
decrease the CIR (Committed Information Rate) transmission quota by an amount corresponding to the size of the protocol data unit in response to the sending of the protocol data unit (CIR transmission quota=CIR transmission quotaprev−PKS), increase the CIR transmission quota by an amount INC_CIR_tx corresponding to the maximum permissible mean value CIR_tx of transmission speed of the traffic flow (CIR transmission quota=CIR transmission quotaprev+INC_CIR_tx), and determine whether the sending of the next protocol data unit should be delayed in order to meet the condition set on the transmission speed, by comparing a momentary value of the CIR transmission quota to a predetermined threshold value K_CIR_tx. The principle described above is often referred to as the token bucket principle. The amount INC_CIR_tx is advantageously CIR_tx�time which has passed from the previous increase of the CIR transmission quota. The subscript �prev� refers to the value of the CIR transmission quota preceding the increase or decrease. The CIR transmission quota can be increased e.g. at equidistant intervals of time. The predetermined threshold value K_CIR_tx may be zero, for instance. If CIR transmission quota<K_CIR_tx, the sending of the next protocol data unit should be delayed in order to meet the condition set on the transmission speed of the traffic flow. The information 117 can be set e.g. as follows: information 117=�1� if CIR transmission quota<K_CIR_tx, and otherwise information 117=�0�. Information 117 can be updated at moments of time when the CIR transmission quota is decreased in response to the sending of the protocol data unit and at moments of time when the CIR transmission quota is increased. Advantageously a maximum permissible value CIR_max_tx is set for the CIR transmission quota, not to be exceeded by the CIR transmission quota. The difference between the maximum permissible value and the threshold value, CIR_max_tx−K_CIR_tx, represents the burst size [bit] by which the maximum permissible mean value CIR_tx of transmission speed can be temporarily exceeded.
decrease the values for the CIR (Committed Information Rate) transmission quota and PIR (Peak Information Rate) transmission quota by an amount corresponding to the size of the transmitted protocol data unit in response to the sending of the protocol data unit (CIR transmission quota=CIR transmission quotaprev−PKS and PIR transmission quota=PIR transmission quotaprev−PKS), increase the CIR transmission quota by an amount INC_CIR_tx corresponding to the maximum permissible mean value CIR_tx of transmission speed of the traffic flow (CIR transmission quota=CIR transmission quotaprev+INC_CIR_tx), increase the PIR transmission quota by an amount INC_PIR_tx corresponding to the highest permissible maximum value PIR_tx (PIR transmission quota=PIR transmission quotaprev+INC_PIR_tx), and determine whether the sending of the next protocol data unit should be delayed in order to meet a condition set on the transmission speed, by comparing a momentary value of the CIR transmission quota to a predetermined threshold value K_CIR_tx and comparing a momentary value of the PIR transmission quota to a second predetermined threshold value K_PIR_tx. The amount INC_CIR_tx is advantageously CIR_tx�time which has passed from the previous increase of the CIR transmission quota, and the amount INC_PIR_tx is advantageously PIR_tx�time which has passed from the previous increase of the PIR transmission quota. The subscript �prev� refers to the values of the CIR and PIR transmission quotas preceding the increase or decrease. The CIR and PIR transmission quotas can be increased e.g. at equidistant intervals of time. The predetermined threshold values K_CIR_tx and K_PIR_tx may be zeroes, for instance. If PIR transmission quota<K_PIR_tx or CIR transmission quota<K_CIR_tx, the sending of the next protocol data unit should be delayed in order to meet the condition set on the transmission speed of the traffic flow. The information 117 can be set e.g. as follows: information 117=�1� if CIR transmission quota<K_CIR_tx OR PIR transmission quota<K_PIR_tx, and otherwise information 117=�0�. Information 117 can be updated at moments of time when the CIR and PIR transmission quotas are decreased in response to the sending of the protocol data unit and at moments of time when the CIR and PIR transmission quotas are increased. Advantageously the PIR transmission quota is not increased over the threshold value K_PIR_tx because PIR_tx represents the highest permissible maximum value of transmission speed.
T=T � rx+PKS/S � rx. (6)
S_rx is the maximum permissible value of the speed of arrival and T is the moment of time earlier to which the value of the speed of arrival exceeds the maximum permissible value and later to which the value of the speed of arrival remains below the maximum permissible value. Time T is valid only if the protocol data unit is the last-arrived protocol data unit belonging to traffic category B. Time T is redetermined, based on equation (6), in response to the arrival of the next protocol data unit belonging to traffic category B. Time T represents a piece of information 118 which indicates together with current time t whether the speed of arrival of traffic representing traffic category B meets a condition set on it. The information 118 can be set e.g. as follows: information 118=�1� if current time t<T, and �0� if t≧T.
decrease the CIR reception quota by an amount corresponding to the size of the protocol data unit in response to the reception of the protocol data unit (CIR reception quota=CIR reception quotaprev−PKS), increase the CIR reception quota by an amount INC_CIR_rx corresponding to the maximum permissible mean value CIR_rx of the speed of arrival of traffic representing traffic category B (CIR reception quota=CIR reception quotaprev+INC_CIR_rx), and determine whether the speed of arrival meets a preset condition by comparing a momentary value of the CIR reception quota to a predetermined threshold value K_CIR_rx. The amount INC_CIR_rx is advantageously CIR_rx�time which has passed from the previous increase of the CIR reception quota. The subscript �prev� refers to the value of the CIR reception quota preceding the increase or decrease. The CIR reception quota may be increased in response to at least one of the following events, for example: reception of a protocol data unit, transmission of a protocol data unit, the current time reaching one of predetermined update moments which may occur at equidistant intervals, for example. The predetermined threshold value K_CIR_rx may be zero, for instance. If the CIR reception quota<K_CIR_rx, the speed of arrival does not meet the condition set on it. The result from the comparison between the CIR reception quota and threshold value represents the information 118 which indicates whether the speed of arrival meets the condition set on it. The information 118 can be set e.g. as follows: information 118=�1� if CIR reception quota<K_CIR_rx, and otherwise information 118=�0�. Information 118 can be updated at moments of time when the CIR reception quota is decreased in response to reception of a protocol data unit and at moments of time when the CIR reception quota is increased. Advantageously a maximum permissible value CIR_max_rx is set for the CIR reception quota, not to be exceeded by the CIR reception quota. The difference between the maximum permissible value and the threshold value, CIR_max_rx−K_CIR_rx, represents the burst size [bit] by which the maximum permissible mean value CIR_rx of the speed of arrival can be temporarily exceeded.
decrease the CIR reception quota and PIR reception quota by an amount corresponding to the size of the protocol data unit in response to the reception of the protocol data unit (CIR reception quota=CIR reception quotaprev−PKS, and PIR reception quota=PIR reception quotaprev−PKS), increase the CIR reception quota by an amount INC_CIR_rx corresponding to the maximum permissible mean value CIR_rx of the speed of arrival of traffic representing traffic category B (CIR reception quota=CIR reception quotaprev+INC_CIR_rx), increase the PIR reception quota by an amount INC_PIR_rx corresponding to the maximum permissible value PIR_rx of the speed of arrival (PIR reception quota=PIR reception quotaprev+INC_PIR_rx), determine whether the speed of arrival meets the preset condition by comparing a momentary value of the CIR reception quota to a predetermined threshold value K_CIR_rx, and determine whether the speed of arrival meets a second preset condition by comparing a momentary value of the PIR reception quota to a second predetermined threshold value K_PIR_rx. The amount INC_CIR_rx is advantageously CIR_rx�time which has passed from the previous increase of the CIR reception quota, and the amount INC_PIR_rx is advantageously PIR_rx�time which has passed from the previous increase of the PIR reception quota. The subscript �prev� refers to the values of the CIR and PIR reception quotas preceding the increase or decrease. The CIR and PIR reception quotas may be increased in response to at least one of the following events, for example: reception of a protocol data unit, transmission of a protocol data unit, the current time reaching one of predetermined update moments which may occur at equidistant intervals, for example. The predetermined threshold values K_CIR_rx and K_PIR_rx may be zeroes, for instance. The result from the comparison between the CIR reception quota and threshold value K_CIR_rx represents the information 118 which indicates whether the speed of arrival meets the condition set on it and whether the protocol data units belonging to traffic category B (delay-critical) will be delayed like protocol data units belonging to traffic category A (non-delay-critical). The information 118 can be set e.g. as follows: information 118 =�1� if CIR reception quota<K_CIR_rx, and otherwise information 118=�0�. Information 118 can be updated at moments of time when the CIR and PIR reception quotas are decreased in response to reception of a protocol data unit and at moments of time when the CIR and PIR reception quotas are increased. The result from the comparison between the PIR reception quota and threshold value K_PIR_rx represents information 118 which indicates whether traffic representing traffic category B will be limited by discarding or marking protocol data units belonging to traffic category B. If a protocol data unit representing traffic category B is discarded, the decrease operations of the CIR and PIR reception quotas relating to the reception of that protocol data unit are advantageously cancelled or left undone because the discarded protocol data unit has been removed from traffic and thus is not using up the CIR or PIR reception quotas.
In an equipment 101 according to an embodiment of the invention functional part 106 is arranged to receive from the system 108 a piece of information 111 indicating the size PKS [bit] of a received protocol data unit belonging to traffic category B and the reception moment T_rx of the starting point of the protocol data unit (start time of reception). Functional part 106 is arranged to compare the reception moment T_rx to the CIR theoretical arrival time TAT_CIR, and the PIR theoretical arrival time TAT_PIR. The mean speed of arrival of traffic representing traffic category B exceeds the maximum permissible value CIR_rx, if T_rx<TAT_CIR. The speed of arrival exceeds the highest permissible maximum value PIR_rx, if T_rx<TAT_PIR. The reception time T_rx and theoretical arrival times TAT_CIR and TAT_PIR are advantageously used such that protocol data units belonging to traffic category B are delayed similarly as protocol data units belonging to traffic category A if T_rx<TAT_CIR, and protocol data unit(s) belonging to traffic category B is/are discarded or marked if T_rx<TAT_PIR. The information 118 can be set e.g. as follows: information 118=�1� if T_rx<TAT_CIR, and otherwise information 118=�0�. Information 116, on the basis of which protocol data units belonging to traffic category B are discarded or marked, can be set as follows, for example: information 116=�1� if T_rx<TAT_PIR, and otherwise information 116=�0�.
TAT_CIRnext=max{T � rx−CBS� rx/CIR� rx, TAT_CIR}+PKS/CIR� rx, (7)
TAT_PIRnext=T � rx+PKS/PIR� rx, (8)
where CBS_rx (Committed Burst Size) is the burst size [bit] within the limits of which the speed of arrival can temporarily exceed the value CIR_rx. The subscript �next� refers to the updated CIR and PIR theoretical arrival times compared with the reception time of the next-to-arrive protocol data unit of traffic category B. If a protocol data unit representing traffic category B is discarded, the updates according to equations (7) and (8) relating to the reception of that protocol data unit are advantageously cancelled or left undone because the discarded protocol data unit has been removed from traffic and thus is not having an effect on the speed of arrival.
S � B=PKSprev/(T � tx−T � txprev) (9)
in response to a situation in which the transmitted protocol data unit belongs to traffic category B. PKSprev refers to the size of the previously transmitted protocol data unit belonging to traffic category B, and T_txprev refers to the starting moment of the transmission of the previously transmitted protocol data unit. Values PKSprev and T_txprev have been received from the system 108 in connection with the sending of the previously transmitted protocol data unit. Transmission speed of traffic representing traffic category B meets the preset condition if S_B is equal to or smaller than the maximum permissible transmission speed S_Btx of traffic representing traffic category B. The information 118 can be set e.g. as follows: information 118=�1� if S_B>S_Btx, and otherwise information 118=�0�.
decrease the CIR_B transmission quota by an amount corresponding to the size of the protocol data unit in response to the sending of the protocol data unit (CIR_B transmission quota=CIR_B transmission quotaprev−PKS), increase the CIR_B transmission quota by an amount INC_CIR_B_tx corresponding to the maximum permissible mean value CIR_B_tx of traffic representing traffic category B (CIR_B transmission quota=CIR_B transmission quotaprev+INC_CIR_B_tx), and determine whether the transmission speed of traffic representing traffic category B meets a preset condition by comparing a momentary value of the CIR_B transmission quota to a predetermined threshold value K_CIR_B_tx. The amount INC_CIR_tx is advantageously CIR_B_tx�time which has passed from the previous increase of the CIR_B transmission quota. The subscript �prev� refers to the value of the CIR_B transmission quota preceding the increase or decrease. The CIR_B transmission quota may be increased in response to at least one of the following events, for example: transmission of a protocol data unit, and the occurrence of current time reaching one of predetermined update moments which may occur at equidistant intervals, for example. The predetermined threshold value K_CIR_B_tx may be zero, for instance. If CIR_B transmission quota<K_CIR_B_tx, the transmission speed of traffic representing traffic category B does not meet the condition set on it. The result from the comparison between the CIR_B transmission quota and threshold value represents the information 118 which indicates whether the transmission speed meets the condition set on it. The information 118 can be set e.g. as follows: information 118=�1� if CIR_B transmission quota<K_CIR_B_tx, and otherwise information 118=�0�. Information 118 can be updated at moments of time when the CIR_B transmission quota is decreased in response to the sending of the protocol data unit and at moments of time when the CIR_B transmission quota is increased. Advantageously a maximum permissible value CIR_B_max_tx is set for the CIR_B transmission quota, and the CIR_B transmission quota shall not be increased over that value. The difference between the maximum permissible value and the threshold value, CIR_B_max_tx−K_CIR_B_tx, represents the burst size [bit] by which the maximum permissible mean value CIR_B_tx of transmission speed can be temporarily exceeded.
T_next=T � tx+PKS/S � tx whether the sending of the next protocol data unit should be delayed in order to meet the condition set on the transmission speed. T_tx is the sending moment of the starting point of the protocol data unit transmitted, PKS is the size of the protocol data unit transmitted, S_tx is the maximum permissible transmission speed, and T_next is the earliest moment of time at which the next protocol data unit can be sent without exceeding the maximum permissible transmission speed.
T=T � rx+PKS/S� rx where T_rx is the moment of arrival of the starting point of the last-arrived protocol data unit belonging to traffic category B, PKS is the size of the protocol data unit, S_rx is the maximum permissible value of the speed of arrival, and T is the moment of time earlier to which the value of the speed of arrival exceeds the maximum permissible value and later to which the value of the speed of arrival remains below the maximum permissible value.
Referenced byCiting PatentFiling datePublication dateApplicantTitleUS20120020227 *Oct 7, 2010Jan 26, 2012Fiber Logic Communications, Inc.Complementary network quality testing methodUS20120290810 *Apr 18, 2012Nov 15, 2012Jean-Jacques LeclerMemory Access Latency Metering* Cited by examinerClassifications U.S. Classification370/235International ClassificationH04L12/26Cooperative ClassificationH04L47/283, H04L47/22, H04L47/20, H04L47/2416, H04L47/2441, H04L47/10European ClassificationH04L47/22, H04L47/28A, H04L47/24B, H04L47/24D, H04L47/20, H04L47/10Legal EventsDateCodeEventDescriptionJun 18, 2009ASAssignmentOwner name: TELLABS OY ET AL, FINLANDFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:LAULAINEN, MIKKO;REEL/FRAME:022841/0311Effective date: 20090611RotateOriginal ImageGoogle Home - Sitemap - USPTO Bulk Downloads - Privacy Policy - Terms of Service - About Google Patents - Send FeedbackData provided by IFI CLAIMS Patent Services©2012 Google