【文章內(nèi)容簡(jiǎn)介】 : 0 PacketMIA: 0 PacketLateArrival: 0 InternalError: 0 Busies: 0 Jitter Values: MinOfPositivesSD: 1 MaxOfPositivesSD: 1 NumOfPositivesSD: 249 SumOfPositivesSD: 249 Sum2PositivesSD: 249 MinOfNegativesSD: 1 MaxOfNegativesSD: 2 NumOfNegativesSD: 238 SumOfNegativesSD: 239 Sum2NegativesSD: 241 MinOfPositivesDS: 1 MaxOfPositivesDS: 1 NumOfPositivesDS: 97 SumOfPositivesDS: 97 Sum2PositivesDS: 97 MinOfNegativesDS: 1 MaxOfNegativesDS: 1 NumOfNegativesDS: 92 SumOfNegativesDS: 92 Sum2NegativesDS: 92 Interarrival jitterout: 0 Interarrival jitterin: 0 One Way Values: NumOfOW: 0 OWMinSD: 0 OWMaxSD: 0 OWSumSD: 0 OWSum2SD: 0 OWMinDS: 0 OWMaxDS: 0 OWSumDS: 0 OWSum2DS: 0 表7：show rtr collectionstatistics的各域的說(shuō)明 字段說(shuō)明NumOfRTT 成功的往返次數(shù) RTTSum 全程時(shí)間總和 RTTSum2 全程時(shí)間平方和 PacketLossSD 源到目的丟失的包 PacketLossDS 目的到源丟失的包PacketOutOfSequence 返回包序列號(hào)不正確的數(shù)量PacketMIA 出現(xiàn)丟包，但方向不能確定，這通訊是一個(gè)測(cè)試流的最后一個(gè)包丟了。 PacketLateArrival 在超時(shí)之后到達(dá)的包的數(shù)量 InternalError 由于其它內(nèi)部錯(cuò)誤導(dǎo)致作業(yè)不能正常運(yùn)行的次數(shù) Busies 由于上次運(yùn)行未完成而導(dǎo)致本次不能運(yùn)行的次數(shù)＝MinOfPositivesSDMaxOfPositivesSD 源到目的的最小和最大正抖動(dòng)（單位為MS） NumOfPositivesSD 源到目的正抖動(dòng)數(shù)量 SumOfPositivesSD 源到目的總的抖動(dòng)值 Sum2PositivesSD 源到目的正抖動(dòng)的平方和 MinOfNegativesSDMaxOfNegativesSD 目的到源的最小和最大正抖動(dòng)（單位為MS） NumOfNegativesSD 目的到源正抖動(dòng)數(shù)量 SumOfNegativesSD 目的到源總的抖動(dòng)值 Sum2NegativesSD 目的到源正抖動(dòng)的平方和 應(yīng)用于VoIP的UDP抖動(dòng)作業(yè) 這一類(lèi)UDP抖動(dòng)作業(yè)是在當(dāng)前的UDP抖動(dòng)作業(yè)基礎(chǔ)上的一個(gè)增強(qiáng)與擴(kuò)展，經(jīng)過(guò)增強(qiáng)與擴(kuò)展之后，經(jīng)命令行或MIB配置，可以通過(guò)模擬codec來(lái)實(shí)現(xiàn)對(duì)語(yǔ)音質(zhì)量的測(cè)試并直接得出語(yǔ)音質(zhì)量評(píng)分，(4)T可以支持如下幾種codec: 216。 711 A Law 216。 u Law 216。 命令如下： (config) Rtr 1(configrtr) type jitter destipaddr ipaddress destport portno codec codectype codecinterval value codecsize value codecnumpacket value新的參數(shù)的選項(xiàng)如下表所示：CodectypecodecsizecodecintervalcodecnumpacketsG711ulaw17220 ms1000G711alaw17220 ms1000G729a3220 ms1000VoIP作業(yè)使用ICPIF語(yǔ)音質(zhì)量評(píng)價(jià)系統(tǒng)事測(cè)試MOS值，可以通過(guò)命令行和MIB存取活動(dòng)的測(cè)試結(jié)果中的MOS值。這個(gè)測(cè)試可以從應(yīng)用的角度看出來(lái)網(wǎng)絡(luò)性能參數(shù)對(duì)VoIP的支持程度。雖然ICPIF/MOS參數(shù)在評(píng)價(jià)語(yǔ)音質(zhì)量時(shí)是非常有用的，但它并沒(méi)有包括能夠影響到語(yǔ)音質(zhì)量的所有參數(shù)。更詳細(xì)的信息可以參見(jiàn)如下的文檔：IOS (7)T提供了基于單向抖動(dòng)、丟包情況、延時(shí)及MOS/ICPIF語(yǔ)音得分參數(shù)設(shè)置反應(yīng)閾值或發(fā)出SNMP trap的能力，詳細(xì)情況可以參見(jiàn)如下鏈接： (7)T下測(cè)試通過(guò)： logging on rtr 10 type jitter destipaddr destport 16384 codec g711alaw advantagefactor 2 owner admin tag jitterwithvoicescores rtr schedule 10 starttime now rtr reactionconfiguration 10 react mos thresholdtype immediate\ thresholdvalue 490 250 actiontype trapOnly rtr logging traps snmpserver host version 2c public snmpserver enable traps syslog (7)T中的trap的實(shí)質(zhì)是syslog到traps的轉(zhuǎn)換，因此需要在命令行配置logging，在以后的版本中將提供純粹的SNMP trap. 下面是相關(guān)Show的結(jié)果 Router show rtr operationalstate 10 Entry number: 10 Modification time: 12:57: UTC Sun Oct 26 2003 Number of operations attempted: 1 Number of operations skipped: 0 Current seconds left in Life: Forever Operational state of entry: Active Last time this entry was reset: Never Connection loss occurred: FALSE Timeout occurred: FALSE Over thresholds occurred: FALSE Latest RTT (milliseconds): 19 Latest operation start time: 12:57: Sun Oct 26 2003 Latest operation return code: OK ! Voice Scores: ICPIF: 20 MOS Score: 3 ! RTT Values: NumOfRTT: 10 RTTAvg: 19 RTTMin: 19 RTTMax: 20 RTTSum: 191 RTTSum2: 3649 Packet Loss Values: PacketLossSD: 0 PacketLossDS: 0 PacketOutOfSequence: 0 PacketMIA: 0 PacketLateArrival: 0 InternalError: 0 Busies: 0 Jitter Values: NumOfJitterSamples: 9 MinOfPositivesSD: 0 MaxOfPositivesSD: 0 NumOfPositivesSD: 0 SumOfPositivesSD: 0 Sum2PositivesSD: 0 MinOfNegativesSD: 0 MaxOfNegativesSD: 0 NumOfNegativesSD: 0 SumOfNegativesSD: 0 Sum2NegativesSD: 0 MinOfPositivesDS: 1 MaxOfPositivesDS: 1 NumOfPositivesDS: 1 SumOfPositivesDS: 1 Sum2PositivesDS: 1 MinOfNegativesDS: 1 MaxOfNegativesDS: 1 NumOfNegativesDS: 1 SumOfNegativesDS: 1 Sum2NegativesDS: 1 Interarrival jitterout: 0 Interarrival jitterin: 0 One Way Values: NumOfOW: 0 OWMinSD: 0 OWMaxSD: 0 OWSumSD: 0 OWSum2SD: 0 OWMinDS: 0 OWMaxDS: 0 OWSumDS: 0 OWSum2DS: 0 Router show rtr collectionstatistics 10 Entry number: 10 Start Time Index: 12:57: UTC Sun Oct 26 2003 Number of successful operations: 60 Number of operations over threshold: 0 Number of failed operations due to a Disconnect: 0 Number of failed operations due to a Timeout: 0 Number of failed operations due to a Busy: 0 Number of failed operations due to a No Connection: 0 Number of failed operations due to an Internal Error: 0 Number of failed operations due to a Sequence Error: 0 Number of failed operations due to a Verify Error: 0 Voice Scores: MinOfICPIF: 2 MaxOfICPIF: 20 MinOfMos: 3 MaxOfMos: 5 RTT Values: NumOfRTT: 600 RTTAvg: 20 RTTMin: 19 RTTMax: 22 RTTSum: 12100 RTTSum2: 244292 Packet Loss Values: PacketLossSD: 0 PacketLossDS: 0 PacketOutOfSequence: 0 PacketMIA: 0 PacketLateArrival: 0 InternalError: 0 Busies: 0 Jitter Values: NumOfJitterSamples: 540 MinOfPositivesSD: 1 MaxOfPositivesSD: 1 NumOfPositivesSD: 26 SumOfPositivesSD: 26 Sum2PositivesSD: 26 MinOfNegativesSD: 1 MaxOfNegativesSD: 1 NumOfNegativesSD: 19 SumOfNegativesSD: 19 Sum2NegativesSD: 19 MinOfPositivesDS: 1 MaxOfPositivesDS: 1 NumOfPositivesDS: 43 SumOfPositivesDS: 43 Sum2PositivesDS: 43 MinOfNegativesDS: 1 MaxOfNegativesDS: 2 NumOfNegativesDS: 43 SumOfNegativesDS: 44 Sum2NegativesDS: 46 Interarrival jitterout: 0 Interarrival jitterin: 0 One Way Values: NumOfOW: 0 OWMinSD: 0 OWMaxSD: 0 OWSumSD: 0 OWSum2SD: 0 OWMinDS: 0 OWMaxDS: 0 OWSumDS: 0 OWSum2DS: 0. ICMP Echo作業(yè)ICMP Echo作業(yè)可以測(cè)試Cisco 路由器和IP設(shè)備之間的端到端的響應(yīng)時(shí)間，響應(yīng)時(shí)間是通過(guò)計(jì)算ICMP echo請(qǐng)求與響應(yīng)消息的時(shí)間差也教育處的。IP SLA通過(guò)在IP包中設(shè)置DSCP位，也允許用戶(hù)測(cè)量QOS的實(shí)施情況。 響應(yīng)時(shí)間計(jì)算 如以前討論的一樣，在計(jì)算時(shí)，處理延時(shí)被最小化并在最終結(jié)果中減去。 圖6：ICMP echo作業(yè)的響應(yīng)時(shí)間計(jì)算 　ICMP 荷載通過(guò)設(shè)置”request size”用戶(hù)可以配置ICMP ECHO作業(yè)的有效荷載尺寸，路由器將在定義的數(shù)值之上加上36 Bytes，如定義的requestsize是28Bytes，則實(shí)際的ICMP包的大小是64Bytes。 　配置ICMP echo作業(yè)(config)rtr 2(configrtr)type echo protocol ipicmpecho (configrtrecho)requestdatasize 400(configrtrecho)tos 160(config)rtr sch