Mediatrace utilizado para aislar las deficiencias de la red

Introducción

Este documento describe cómo utilizar la función Mediatrace para aislar rápidamente las deficiencias de la red, como la pérdida de paquetes y la fluctuación, que afectan a la calidad de voz y vídeo.

Prerequisites

Requirements

No hay requisitos específicos para este documento.

Componentes Utilizados

La información que contiene este documento se basa en las siguientes versiones de software y hardware.

• Función Mediatrace en las plataformas Cisco Integrated Services Routers (ISR) e ISRG2 - Cisco IOS® versión 15.1(3)T o posterior
• Función Mediatrace en las plataformas Cisco 3750 - Cisco IOS Release 12.2(58)SE o posterior
• Función Mediatrace en Cisco TelePresence EX90 - Software Cisco TelePresence versión TE 6.0 o posterior

The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command.

Convenciones

Consulte Convenciones de Consejos Técnicos de Cisco para obtener más información sobre las convenciones sobre documentos.

Topología de red

En este ejemplo, se explica la configuración de una videollamada que experimenta pérdida de paquetes entre dos terminales EX90. La topología de red se muestra aquí:

Configuración

El proceso para configurar el iniciador y el respondedor de Mediatrace es muy sencillo. Consulte estos ejemplos para ver la configuración.

Central-SW

interface Vlan201
 ip address 10.2.3.70 255.255.255.0

ip rsvp snooping

mediatrace responder
mediatrace initiator source-ip 10.2.3.70 max-sessions 100

WAN central

interface GigabitEthernet0/0
 description "CE router connected to MPLS PE router"
 ip address 10.16.1.2 255.255.255.252
 ip rsvp source address 10.2.3.65
!
interface GigabitEthernet0/1
 description "Connected to Central-SW"
 ip address 10.2.3.65 255.255.255.0

mediatrace responder
mediatrace initiator source-ip 10.2.3.65 max-sessions 100

BR-WAN

interface GigabitEthernet0/0
 description "CE router connected to MPLS PE router"
 ip address 10.16.2.2 255.255.255.252
 ip rsvp source address 10.2.4.65
!
interface GigabitEthernet0/1
 description "Connected to BR3-SW"
 ip address 10.2.4.65 255.255.255.0

mediatrace responder
mediatrace initiator source-ip 10.2.4.65 max-sessions 100

BR-SW

interface Vlan202
 ip address 10.2.4.70 255.255.255.0

ip rsvp snooping

mediatrace responder
mediatrace initiator source-ip 10.2.4.70 max-sessions 100

Metodología de solución de problemas

Cisco recomienda que habilite Mediatrace en todos los nodos aplicables de la red de la empresa. Se admite en plataformas comunes de switching y routing como 3750 e ISR-G2.

Paso 1

Identifique la dirección IP de origen y de destino/número de puerto del flujo de interés del protocolo de tabla de enrutamiento de audio o vídeo (RTP).

EX90

xstatus MediaChannels
*s MediaChannels Call 9 IncomingAudioChannel 115 Encryption Status: Off
*s MediaChannels Call 9 IncomingAudioChannel 115 Audio Protocol: AACLD
*s MediaChannels Call 9 IncomingAudioChannel 115 Audio Mute: False
*s MediaChannels Call 9 IncomingAudioChannel 115 Audio Channels: 1
*s MediaChannels Call 9 IncomingAudioChannel 115 Transport RTP Local IpAddress: 
   "10.2.3.41"
*s MediaChannels Call 9 IncomingAudioChannel 115 Transport RTP Local Port: 16454
*s MediaChannels Call 9 IncomingAudioChannel 115 Transport RTP Remote IpAddress: 
   "10.2.4.5"
*s MediaChannels Call 9 IncomingAudioChannel 115 Transport RTP Remote Port: 16444
*s MediaChannels Call 9 IncomingAudioChannel 115 Transport RTCP Local IpAddress: 
   "10.2.3.41"
*s MediaChannels Call 9 IncomingAudioChannel 115 Transport RTCP Local Port: 16455
*s MediaChannels Call 9 IncomingAudioChannel 115 Transport RTCP Remote IpAddress: 
"10.2.4.5"
*s MediaChannels Call 9 IncomingAudioChannel 115 Transport RTCP Remote Port: 16445
*s MediaChannels Call 9 IncomingVideoChannel 118 Encryption Status: Off
*s MediaChannels Call 9 IncomingVideoChannel 118 ChannelRole: Main
*s MediaChannels Call 9 IncomingVideoChannel 118 Video Protocol: H264
*s MediaChannels Call 9 IncomingVideoChannel 118 Video FrameRate: 30
*s MediaChannels Call 9 IncomingVideoChannel 118 Video ResolutionX: 640
*s MediaChannels Call 9 IncomingVideoChannel 118 Video ResolutionY: 360
*s MediaChannels Call 9 IncomingVideoChannel 118 Transport RTP Local IpAddress: 
   "10.2.3.41"
*s MediaChannels Call 9 IncomingVideoChannel 118 Transport RTP Local Port: 16456
*s MediaChannels Call 9 IncomingVideoChannel 118 Transport RTP Remote IpAddress: 
"10.2.4.5"
*s MediaChannels Call 9 IncomingVideoChannel 118 Transport RTP Remote Port: 16446
*s MediaChannels Call 9 IncomingVideoChannel 118 Transport RTCP Local IpAddress: 
"10.2.3.41"
*s MediaChannels Call 9 IncomingVideoChannel 118 Transport RTCP Local Port: 16457
*s MediaChannels Call 9 IncomingVideoChannel 118 Transport RTCP Remote IpAddress: 
"10.2.4.5"
*s MediaChannels Call 9 IncomingVideoChannel 118 Transport RTCP Remote Port: 16447
*s MediaChannels Call 9 IncomingVideoChannel 121 Encryption Status: Off

Paso 2

Identifique el switch al que está conectado el extremo de origen. Este switch se puede identificar con los comandos show de Cisco Discovery Protocol (CDP).

EX90

xstatus Network
*s Network 1 Ethernet MacAddress: "FF:FF:FF:70:E6:B6"
*s Network 1 Ethernet Speed: 100full
*s Network 1 IPv4 Address: "10.2.3.41"
*s Network 1 IPv4 SubnetMask: "255.255.255.0"
*s Network 1 IPv4 Gateway: "10.2.3.65"
*s Network 1 IPv4 DNS Domain Name: ""
*s Network 1 IPv4 DNS Server 1 Address: ""
*s Network 1 IPv4 DNS Server 2 Address: ""
*s Network 1 IPv4 DNS Server 3 Address: ""
*s Network 1 IPv4 DNS Server 4 Address: ""
*s Network 1 IPv4 DNS Server 5 Address: ""
*s Network 1 IPv6 Address: ""
*s Network 1 IPv6 Gateway: ""
*s Network 1 MTU: 1500
*s Network 1 VLAN Voice VlanId: "201"
*s Network 1 VLAN Native VlanId: "202"
*s Network 1 CDP Platform: "cisco WS-C3750V2-24TS"
*s Network 1 CDP Version: "Cisco IOS Software, C3750 Software 
   (C3750-IPSERVICESK9-M), Version 12.2(58)SE2, RELEASE SOFTWARE (fc1)
   *Technical Support: http://www.cisco.com/techsupport*Copyright (c) 
   1986-2011 by Cisco Systems, Inc.*Compiled Thu 21-Jul-11 01:53 by 
   prod_rel_team"
*s Network 1 CDP Capabilities: "0x0028"
*s Network 1 CDP DeviceID: "Central-SW"
*s Network 1 CDP PortID: "FastEthernet1/0/23"
*s Network 1 CDP Duplex: "Full"
*s Network 1 CDP VTPMgmtDomain: ""
*s Network 1 CDP Address: "10.2.3.70"
*s Network 1 CDP PrimaryMgmtAddress: "10.2.3.70"
*s Network 1 CDP SysName: ""
*s Network 1 CDP SysObjectID: ""
*s Network 1 CDP VoIPApplianceVlanID: "201"
** end

Paso 3

Inicie sesión en el switch de primer salto y configure un especificador de flujo para identificar de forma exclusiva el flujo RTP. Este especificador de flujo se utiliza en el comando mediatrace poll.

mediatrace flow-specifier RTP
 source-ip 10.2.3.41 source-port 16456
 dest-ip 10.2.4.5 dest-port 16446

Paso 4

Ingrese el comando mediatrace poll.

• Valor de origen - Dirección IP del extremo de UC de origen
• Valor de destino: dirección IP del extremo de UC de destino
• Especificador de flujo: nombre del especificador de flujo que contiene el tuplo de 4 valores para identificar el flujo RTP

#mediatrace poll path-specifier source 10.2.3.41 destination 10.2.4.5
   perf-monitor flow-specifier RTP
Started the data fetch operation.
Waiting for data from hops.
This may take several seconds to complete...
Data received for hop 1
Data received for hop 2
Data received for hop 3
Data received for hop 4
Data fetch complete.
Results:
Data Collection Summary:
  Request Timestamp: 11:00:54.302 EST Sun Mar 10 2013
  Request Status: Completed
  Number of hops responded (includes success/error/no-record): 4
  Number of hops with valid data report: 4
  Number of hops with error report: 0
  Number of hops with no data record: 0
Detailed Report of collected data:
    Number of Mediatrace hops in the path: 4

    Mediatrace Hop Number: 1 (host=Central-Wan, ttl=254)
      Metrics Collection Status: Success
      Reachability Address: 10.2.3.65
      Ingress Interface: Gi0/1
      Egress Interface: Gi0/0
      Metrics Collected:
        Flow Sampling Start Timestamp: 10:26:48
        Loss of measurement confidence: FALSE
        Media Stop Event Occurred: FALSE
        IP Packet Drop Count (pkts): 0
        IP Byte Count (Bytes): 191965
        IP Packet Count (pkts): 402
        IP Byte Rate (Bps): 15996
        Packet Drop Reason: 64
        IP DSCP: 32
        IP TTL: 63
        IP Protocol: 0
        Media Byte Rate Average (Bps): 15058
        Media Byte Count (Bytes): 180709
        Media Packet Count (pkts): 402
        RTP Interarrival Jitter Average (usec): 155
        RTP Packets Lost (pkts): 0
        RTP Packets Expected (pkts): 397
        RTP Packet Lost Event Count: 0
        RTP Loss Percent (%): 0.00

    Mediatrace Hop Number: 2 (host=BR-Wan, ttl=251)
      Metrics Collection Status: Success
      Reachability Address: 10.16.2.2
      Ingress Interface: Gi0/0
      Egress Interface: Gi0/1
      Metrics Collected:
        Flow Sampling Start Timestamp: 09:58:40
        Loss of measurement confidence: FALSE
        Media Stop Event Occurred: FALSE
        IP Packet Drop Count (pkts): 0
        IP Byte Count (Bytes): 331523
        IP Packet Count (pkts): 694
        IP Byte Rate (Bps): 16576
        Packet Drop Reason: 64
        IP DSCP: 32
        IP TTL: 60
        IP Protocol: 0
        Media Byte Rate Average (Bps): 15604
        Media Byte Count (Bytes): 312091
        Media Packet Count (pkts): 694
        RTP Interarrival Jitter Average (usec): 1648
        RTP Packets Lost (pkts): 14
        RTP Packets Expected (pkts): 708
        RTP Packet Lost Event Count: 13
        RTP Loss Percent (%): 1.97

    Mediatrace Hop Number: 3 (host=BR-SW, ttl=251)
      Metrics Collection Status: Success
      Reachability Address: 10.2.4.70
      Ingress Interface: Fa1/0/22
      Egress Interface: Fa1/0/24
      Metrics Collected:
        Flow Sampling Start Timestamp: 22:50:37
        Loss of measurement confidence: FALSE
        Media Stop Event Occurred: FALSE
        IP Packet Drop Count (pkts): 0
        IP Byte Count (Bytes): 505526
        IP Packet Count (pkts): 1059
        IP Byte Rate (Bps): 16850
        Packet Drop Reason: 0
        IP DSCP: 32
        IP TTL: 60
        IP Protocol: 17
        Media Byte Rate Average (Bps): 16144
        Media Byte Count (Bytes): 484346
        Media Packet Count (pkts): 1059
        RTP Interarrival Jitter Average (usec): 1511
        RTP Packets Lost (pkts): 22
        RTP Packets Expected (pkts): 1075
        RTP Packet Lost Event Count: 21
        RTP Loss Percent (%): 2.04

    Mediatrace Hop Number: 4 (host=BR-EX90, ttl=251)
      Metrics Collection Status: Success
      Reachability Address: 10.2.4.5
      Ingress Interface: eth0
      Egress Interface: None
      Metrics Collected:
        Flow Sampling Start Timestamp: 11:02:00
        Loss of measurement confidence: FALSE
        Media Stop Event Occurred: FALSE
        IP Packet Drop Count (pkts): 0
        IP Byte Count (Bytes): 0
        IP Packet Count (pkts): 0
        IP Byte Rate (Bps): 0
        Packet Drop Reason: 0
        IP DSCP: 0
        IP TTL: 0
        IP Protocol: 17
        Media Byte Rate Average (Bps): 16000
        Media Byte Count (Bytes): 478219
        Media Packet Count (pkts): 1056
        RTP Interarrival Jitter Average (usec): 4953
        RTP Packets Lost (pkts): 17
        RTP Packets Expected (pkts): 1073
        RTP Packet Lost Event Count: 6
        RTP Loss Percent (%): 0.04

Central-SW#

Análisis de datos

Estas observaciones se pueden hacer desde el resultado del comando mediatrace poll :

1. La ruta de red del flujo RTP contiene 4 dispositivos habilitados para Mediatrace desde Central-SW:
• WAN central
• BR-WAN
• BR-SW
• BR-EX90
2. No se observa pérdida de paquetes en el router de la WAN central.
3. La pérdida de paquetes se observa en BR-WAN, BR-SW y BR-EX90.
4. La conclusión es que se introduce la pérdida de paquetes entre la WAN central y la WAN BR.

Problemas Comunes

Los factores típicos que contribuyen a la pérdida de paquetes son:

1. Valor de punto de código de servicios diferenciados (DSCP) incorrecto.
2. Regulador dentro de la red del proveedor de servicios para limitar la utilización del ancho de banda.
3. Errores de Capa 2, como discordancias dúplex y errores de controlador.

Preguntas Frecuentes

P. ¿Está Mediatrace integrado con sistemas de supervisión o gestión de redes?

A. Sí, Cisco Prime Collaboration permite a los administradores resolver problemas de videollamadas con el uso de Mediatrace con un solo clic y muestra los resultados en formato gráfico.

P. ¿Necesito habilitar el protocolo de reserva de recursos (RSVP) para la función Mediatrace?

A. No, Mediatrace utiliza RSVP-TP que se habilita automáticamente cuando se configura el iniciador o el respondedor de Mediatrace. No es necesario ingresar el comando ip rsvp bandwidth.

Información Relacionada

• Soporte Técnico y Documentación - Cisco Systems

Historial de revisiones