 Feedback
|
Table Of Contents
MGX-RPM-1FE-CP Back Card Installation and Configuration Note
PPP Multiplexing/Demultiplexing
MGX-RPM-1FE-CP Back Card in an IP-RAN
Physical Characteristics of the MGX-RPM-1FE-CP Back Card
Installing the MGX-RPM-1FE-CP Back Card
Removing the MGX-RPM-1FE-CP Back Card
Configuring the MGX-RPM-1FE-CP Back Card
Verifying the Version of IOS Software
Configuring the FE Interface IP Address
Setting the Speed and Duplex Mode
Configuring Routing Protocol Attributes
Configuring Multilink Interfaces
Configuring the Loopback Interface
Configuring IP Address Assignment
Configuring ACFC and PFC Handling During PPP Negotiation
Configuring RTP/UDP Compression
Configuring the RTP/UDP Compression Flow Expiration Timeout Duration
Configuring Routing Protocol Attributes
Enabling Link Quality Monitoring (LQM)
Configuring the Switch Interface and PVCs
Verifying the Configuration of the MGX-RPM-1FE-CP Back Card
Monitoring and Managing the MGX-RPM-1FE-CP Back Card
clear ip rtp header-compression
ip rtp compression-connections
show ip rtp header-compression
Obtaining Technical Assistance
Contacting TAC by Using the Cisco TAC Website
MGX-RPM-1FE-CP Back Card Installation and Configuration Note
This document contains the following sections:
•
Installing the MGX-RPM-1FE-CP Back Card
•
•
•
Overview
The MGX-RPM-1FE-CP (one-port, Fast Ethernet-Co-processor) back card is an MGX8850/RPM-PR back card that off-loads the following processes from the Route Processor Module (RPM-PR):
•
•
The MGX-RPM-1FE-CP back card is designed to be used with an MGX8850 that is equipped with one or more RPM-PRs and that terminates some number of T1 lines. Each MGX-RPM-1FE-CP back card has a termination capacity of up to eight T1s (four per Multilink PPP [MLP] bundle). The MGX-RPM-1FE-CP is only supported with the MLP encapsulation.
The MGX-RPM-1FE-CP back card contains one Fast Ethernet (100Base-Tx) interface. The interface has an RJ45 connector that is used to connect the card to a Category 5 un-shielded twisted pair (UTP) cable. Both half- and full-duplex operation are supported.
PPP Multiplexing/Demultiplexing
Encapsulated PPP frames contain several bytes of header information, which adds considerable overhead to a network that is used to transport PPP frames.
RFC 3153, PPP Multiplexing, describes a way to overcome this overhead. On the sending end, a multiplexor concatenates multiple PPP frames (subframes) into a single, multiplexed frame (superframe). One header is included in the superframe and the individual PPP subframes are separated by delimiters. On the receiving end, a demultiplexor uses the delimiters to separate the individual PPP subframes.
The MGX-RPM-1FE-CP back card conforms to this specification and acts as both a multiplexor and a demultiplexor.
RTP/UDP Header Compression
RTP is a protocol used for carrying packetized audio and video traffic over an IP network. RTP, described in RFC 1889, is not intended for data traffic, which uses TCP or UDP. Instead, RTP provides end-to-end network transport functions intended for applications with real-time requirements (such as audio, video, or simulation data) over multicast or unicast network services.
In an RTP frame, there is a minimum 12 bytes of the RTP header, combined with 20 bytes of IP header, and 8 bytes of UDP header. This creates a 40-byte IP/UDP/RTP header. By comparison, the RTP packet has a payload of approximately 20 to 160 bytes for audio applications that use compressed payloads. Given this ratio, it is very inefficient to transmit the IP/UDP/RTP header without compressing it.
Figure 1 RTP Header Compression
RFCs 2508 and 2509 describe a method for compressing not only the RTP header, but also the associated UDP and IP headers. Using this method, the 40 bytes of header information is compressed into approximately 2 to 4 bytes, as shown in Figure 1. Because the frames are compressed on a link-by-link basis, the delay and loss rate are lower, resulting in improved performance.
The MGX-RPM-1FE-CP back card offloads both the compression and decompression of RTP frames from the RPM-PR.
Note
MGX-RPM-1FE-CP Back Card in an IP-RAN
The MGX-RPM-1FE-CP back card off loads the compression/decompression of RTP/UDP headers and the multiplexing/ demultiplexing of PPP frames.
The supported use of the MGX-RPM-1FE-CP back card is within an IP-RAN of a mobile wireless network. In mobile wireless networks, radio coverage over a geographical space is provided by a network of radios and supporting electronics (Base Transceiver Station [BTS]) distributed over a wide area. Each radio and supporting electronics represents a "cell." In traditional networks, the radio signals or radio data frames collected in each cell are forwarded over a T1 (or similar low-speed, leased) line to a centralized Base Station Controller (BSC) where they are processed.
With the blurring of the lines between voice and data, several alternatives have arisen. One alternative is to replace the T1s with a cell- based AAL2/ATM approach to deliver the frames. This alternative seems to work well because the frame sizes within a wireless network match up nicely with the frame sizes used within an ATM network (10-20 bytes).
Another alternative is to encapsulate the radio frames in UDP frames and transport them over an IP network using header compression and packet multiplexing. This alternative provides better bandwidth efficiency than AAL2 and thus greater backhaul capacity. In this alternative, the MGX 8850 is used as a leased line termination and aggregation device. To enable the delivery of the aggregated back haul IP traffic to and from a routed IP network, the MGX is equipped with RPM-PR blades (which terminate and originate the frames) and MGX-RPM-1FE-CP back cards (which compress and multiplex the frames).
The nature of UDP or RTP header compression is such that compressed packets must be decompressed prior to routing. Also, to optimize network bandwidth, the frames must be multiplexed/compressed before they are sent across the T1 line (and decompressed/demultiplexed before they are sent across the FE interface).
•
•
Multilink PPP (MLP) provides a standardized method for spreading traffic across multiple WAN links, while providing multivendor interoperability, packet fragmentation and proper sequencing, and load-balancing on both inbound and outbound traffic. When used in conjunction with Multilink PPP, the MGX-RPM-1FE-CP back card allows customers to increase channel capacity up to eight T1s.
This solution requires the following components:
•
•
•
•
•
The solution uses Open Shortest Path First (OSPF) as the routing protocol and requires MLP for transmission of the packets between the aggregation node (MGX8850) and the BTS. It requires you to configure the following:
•
•
•
•
In addition, you must configure a connection between the PVC and the FRSM as well as a connection between the FRSM and the PVC.
Physical Characteristics of the MGX-RPM-1FE-CP Back Card
The MGX-RPM-1FE-CP back card has one Fast Ethernet (100Base-Tx) interface that can be connected to an RJ-45 cable. (For more information about the pinout configuration for the connector, see "RJ-45 Pinout Configuration" section.) It also has three LEDs that indicate the state and status of the card and the interface. (For more information about the meanings of these LEDs, see "Understanding the LEDs" section.)
Figure 2 MGX-RPM-1FE-CP Back Card
Table 1 lists the cabling specifications for 100-Mbps Fast Ethernet transmission over UTP cables.
Table 1 Specifications and Connection Limits for 100-Mbps Transmission
Cable specification
Category 5 UTP, 22 to 24 AWG1
Maximum segment length
328 ft (100 m)
Maximum network length
656 ft (200 m) (with 1 repeater)2
1 Cisco Systems does not supply Category 5 UTP RJ-45 cables. These cables are available commercially.
2 This length is specifically between any two stations on a repeated segment.
Installing the MGX-RPM-1FE-CP Back Card
The MGX-RPM-1FE-CP back card must be installed as a back card to an RPM-PR front card. It can be installed in any back slot that corresponds to an RPM-PR front card except reserved slots 31 and 32, which are reserved for the Service Redundancy Modules (SRMs).
Note
Before You Install
Before you install the MGX-RPM-1FE-CP back card, be sure to:
•
Figure 3 Backplane Inspection Check Points
•
Figure 4 Damaged Connectors on Card
Caution
Caution
Installation Steps
To install the MGX-RPM-1FE-CP back card, do the following:
Step 1
Step 2
Step 3
Step 4
Tip
Removing the MGX-RPM-1FE-CP Back Card
A captive screw at the top and bottom of the faceplate of each back card secures the card to the card cage. The extraction levers let you pull the card from the backplane connector after you loosen the captive screws.
To remove the MGX-RPM-1FE-CP back card, do the following:
Step 1
Step 2
Step 3
Configuring the MGX-RPM-1FE-CP Back Card
To configure the MGX-RPM-1FE-CP back card, you must first access the RPM-PR command line interface (CLI). The RPM-PR CLI can be accessed using any of the following three methods:
•
The RPM-PR has an RJ-45 connector on the front of the card module. If you configure the RPM-PR on site, connect a console terminal (an ASCII terminal or a PC running terminal emulation software) directly to the console port on your RPM-PR using an RS-232 to RJ-45 cable for CLI access. The console port is the only way to access the RPM-PR CLI when the card module is first installed into an MGX 8850 chassis.
•
After initial configuration, you can also configure the RPM-PR through the PXM. You can access the RPM-PR CLI by using the cc (change card) command from any of the other cards in the MGX 8850 switch. The ATM switch interface on the RPM-PR must be enabled before you can use the cc command.
•
After initial configuration, you can also configure the RPM-PR remotely via telnet. After the RPM-PR is installed and has PVCs to other RPM-PRs or routers in the network, you can telnet to the RPM-PR CLI remotely from these other devices.
For more information about accessing the RPM-PR CLI and the basic IOS command structure, please see the RPM Installation and Configuration Guide.
Configuration of the MGX-RPM-1FE-CP back card requires the following:
•
•
•
•
•
Verifying the Version of IOS Software
The MGX-RPM-1FE-CP back card requires Cisco IOS Release 12.2(8) MC1 or a later Cisco IOS Release 12.2 MC on the corresponding RPM-PR. To verify the version of IOS software, use the show version command.
The show version command displays the configuration of the system hardware, the software version, the names and sources of configuration files, and the boot images.
Configuring the FE Interface
To configure the FE interface of the MGX-RPM-1FE-CP back card, complete the following tasks:
•
•
•
Configuring the FE Interface IP Address
To configure the FE interface, do the following:
Step 1
RPM-3# configure terminalEnter configuration commands, one per line. End with CNTL/Z.RPM-3(config)#Step 2
RPM-3(config)# interface fastethernet slot/portThe slot is the slot of the MGX8850 where the RPM-PR resides (upper=1, lower=2). The port is the number of the port on the back card.
Step 3
RPM-3(config-if)# ip address x.x.x.x nnn.nnn.nnn.0
Setting the Speed and Duplex Mode
The MGX-RPM-1FE-CP back card can run in full or half duplex mode and at 100 Mbps or 10 Mbps. It also has an auto-negotiation feature that allows the card to negotiate the speed and duplex mode with the corresponding interface on the other end of the connection.
Auto negotiation is the default setting for the speed and transmission mode. However, when using the MGX-RPM-1FE-CP back card in a wireless IP RAN solution, do not use auto negotiation. You must explicitly configure a speed of 100 Mbps and either full- or half-duplex transmission mode.
To configure speed and duplex operation, do the following while still in interface configuration mode:
Step 1
RPM-3(config-if)# duplex [auto | half | full]Step 2
RPM-3(config-if)# speed [auto | 100 | 10]
Configuring Routing Protocol Attributes
When used in the IP-RAN solution, the MGX-RPM-1FE-CP back card must be configured to support the OSPF routing protocol. To configure OSPF routing protocol attributes, do the following while still in interface configuration mode:
Step 1
RPM-3(config-if)# ip ospf message-digest-key key-id md5 keyStep 2
RPM-3(config-if)# ip ospf hello-interval secondsStep 3
RPM-3(config-if)# ip ospf dead-interval seconds
Configuring PIM
Because the MGX-RPM-1FE-CP back card is used in a multicast PPP environment, you should configure the PIM mode of the FE interface.
To configure the PIM mode, do the following while still in interface configuration mode:
Step 1
RPM-3(config-if)# ip pim {sparse-mode | sparse-dense-mode | dense-mode [proxy-register {list access-list | route-map map-name}]}
Enabling the FE Interface
Once you have configured the FE interface, enable it by doing the following:
Step 1
RPM-3(config-if)# no shutdown
Configuring Multilink Interfaces
To configure the multilink interfaces to be used in conjunction with the MGX-RPM-1FE-CP back card, complete the following tasks:
•
•
•
•
Configuring the Loopback Interface
The loopback interface is a software-only, virtual interface that emulates an interface that is always up. The interface-number is the number of the loopback interface that you want to create or configure. There is no limit on the number of loopback interfaces you can create.
Because the multilink interface is a virtual interface, you should create a loopback interface for the multilink interface to enable IP processing on the interface without having to assign an explicit IP address.
To configure a loopback interface for the multilink interface, do the following:
Step 1
RPM-3# configure terminalEnter configuration commands, one per line. End with CNTL/Z.RPM-3(config)#Step 2
RPM-3(config)# interface loopback numberRPM-3(config-if)# ip address ip_address subnet_maskStep 3
RPM-3(config-if)# exit
Configuring Multilink PPP
As higher-speed services are deployed, Multilink-PPP (MLP) provides a standardized method for spreading traffic across multiple WAN links, while providing multivendor interoperability, packet fragmentation and proper sequencing, and load balancing on both inbound and outbound traffic. The MGX-RPM-1FE-CP back card used in conjunction with the Multilink Point-to-Point Protocol (PPP) feature provides customers with the ability to increase channel capacity to up to eight T1s.
A Multilink interface is a special virtual interface which represents a multilink PPP bundle. The multilink interface serves to coordinate the configuration of the bundled link, and presents a single object for the aggregate links. However, the individual PPP links that are aggregated together, must also be configured. Therefore, to enable Multilink PPP on multiple serial interfaces, you need to first set up the multilink interface, and then configure each of the serial interfaces and add them to the same multilink interface.
To set up the multilink interface, do the following:
Step 1
RPM-3(config)# interface multilink numberStep 2
RPM-3(config-if)# ppp multilinkStep 3
RPM-3(config-if)# no ppp multilink fragmentationIf using Cisco IOS Release 12.3(11)T or later, enter the following command to disable PPP multilink fragmentation:
RPM-3(config-if)# ppp multilink fragment disableStep 4
RPM-3(config-if)# multilink-group group-numberIf using Cisco IOS Release 12.3(11)T or later, enter the following command to specify an identification number for the multilink interface:
RPM-3(config-if)# ppp multilink group group-numberStep 5
RPM-3(config-if)# ip unnumbered loopback numberWhere number is the number of the loopback interface that you configured in Configuring the Loopback Interface.
Configuring IP Address Assignment
A point-to-point interface must be able to provide a remote node with its IP address through the IP Control Protocol (IPCP) address negotiation process. The IP address can be obtained from a variety of sources. The address can be configured through the command line, entered with an EXEC-level command, provided by TACACS+ or the Dynamic Host Configuration Protocol (DHCP), or from a locally administered pool.
IP address pooling uses a pool of IP addresses from which an incoming interface can provide an IP address to a remote node through IPCP address negotiation process. IP address pooling also enhances configuration flexibility by allowing multiple types of pooling to be active simultaneously.
To configure IP address assignment, do the following while still in interface configuration mode:
Step 1
RPM-3(config-if)# peer default ip address {ip-address | dhcp | pool [pool-name]}
Configuring PPP Multiplexing
To enable and control the multiplexing of PPP frames, do the following while still in multilink interface configuration mode:
Step 1
RPM-3(config-if)# ppp muxStep 2
To set the maximum time delay, enter:
RPM-3(config-if)# ppp mux delay integerTo set the maximum length of the subframe, enter:
RPM-3(config-if)# ppp mux subframe length integerTo set maximum length of the superframe, enter:
RPM-3(config-if)# ppp mux frame integerTo set the maximum number of subframes in a superframe, enter:
RPM-3(config-if)# ppp mux subframe count integerTo set the default PPP protocol ID, enter:
RPM-3(config-if)# ppp mux pid integer
Configuring ACFC and PFC Handling During PPP Negotiation
With Cisco IOS Release 12.2(15)MC1 and later, ACFC and PFC handling during PPP negotiation can be configured. By default, ACFC/PFC handling is not enabled.
To configure ACFC handling during PPP negotiation, do the following while in multilink interface configuration mode:
Step 1
RPM-3(config-if)# ppp acfc remote {apply | reject | ignore}Where:
•
•
•
Step 2
RPM-3(config-if)# ppp acfc local {request | forbid}Where:
•
•
To configure PFC handling during PPP negotiation, do the following while in multilink interface configuration mode:
Step 1
RPM-3(config-if)# ppp pfc remote {apply | reject | ignore}Where:
•
•
•
Step 2
RPM-3(config-if)# ppp acfc local {request | forbid}Where:
•
•
Configuring RTP/UDP Compression
Enabling RTP/UDP compression (cRTP/cUDP) on both ends of a low-bandwidth serial link can greatly reduce the network overhead if there is a lot of RTP traffic on that slow link. This compression is beneficial especially when the RTP payload size is small (for example, compressed audio payloads of 20-50 bytes).
Before you can enable RTP header compression, you must configure a serial line that uses PPP encapsulation.
To configure RTP header compression, do the following while still in multilink interface configuration mode:
Step 1
RPM-3(config-if)# ip rtp header-compressionIf using Cisco IOS Release 12.3(11)T or later, enable RTP header compression for serial encapsulations and suppress IP ID checking during RTP compression by specifying the ignore-id keyword option:
RPM-3(config-if)# ip rtp header-compression ignore-idStep 2
RPM-3(config-if)# ip rtp compression-connections number
Note
Configuring the RTP/UDP Compression Flow Expiration Timeout Duration
To minimize traffic corruption, cUDP flows expire after a period of time during which no packets are passed. When this user defined duration of inactivity occurs on a flow at the compressor, the compressor sends a full header upon receiving a packet for that flow, or, if no new packet is received for that flow, the compressor makes the CID for the flow available for new use. When a packet is received at the decompressor after the duration of inactivity has been exceeded, the packet is dropped and a context state message is sent to the compressor requesting a flow refresh.
The default expiration timeout is 5 seconds. The recommended value is 8 seconds.
Caution
To configure the duration of the cUDP flow expiration timeout, do the following while in multilink interface configuration mode:
Step 1
RPM-3(config-if)# ppp iphc max-time seconds
Configuring Routing Protocol Attributes
When used in the IP-RAN solution, the multilink interface must be configured to support the OSPF routing protocol. To configure OSPF routing protocol attributes, do the following while still in interface configuration mode:
Step 1
RPM-3(config-if)# ip ospf message-digest-key key-id md5 keyStep 2
RPM-3(config-if)# ip ospf hello-interval secondsStep 3
RPM-3(config-if)# ip ospf dead-interval seconds
Configuring PIM
Because the MGX-RPM-1FE-CP back card is used in a multicast PPP environment, you should configure the PIM mode of the multilink interface.
To configure the PIM mode, do the following while still in interface configuration mode:
Step 1
RPM-3(config-if)# ip pim {sparse-mode | sparse-dense-mode | dense-mode [proxy-register {list access-list | route-map map-name}]}
Configuring Virtual Templates
To configure the virtual templates to be used in conjunction with the MGX-RPM-1FE-CP back card, complete the following tasks:
•
Configuring the IP Address
No IP address should be associated with the virtual template. To configure no IP address, do the following:
Step 1
RPM-3# configure terminalEnter configuration commands, one per line. End with CNTL/Z.RPM-3(config)#Step 2
RPM-3(config)# interface virtual-template numberStep 3
RPM-3(config-if)# no ip address
Configuring Multilink PPP
To associate the virtual template with a multilink group, do the following while still in interface configuration mode:
Step 1
RPM-3(config-if)# ppp multilinkStep 2
RPM-3(config-if)# ppp multilink queue depth qos numberThis command sets the maximum depth for link queues when a bundle has non-FIFO queuing. The possible values are 2 through 255.
Step 3
RPM-3(config-if)# multilink-group group-numberIf using Cisco IOS Release 12.3(11)T or later, enter the following command to specify an identification number for the multilink interface:
RPM-3(config-if)# ppp multilink group group-number
Enabling Link Quality Monitoring (LQM)
Link Quality Monitoring (LQM) is available on all serial interfaces running PPP. LQM will monitor the link quality, and if the quality drops below a configured percentage, the router shuts down the link. The percentages are calculated for both the incoming and outgoing directions. The outgoing quality is calculated by comparing the total number of packets and bytes sent with the total number of packets and bytes received by the destination node. The incoming quality is calculated by comparing the total number of packets and bytes received with the total number of packets and bytes sent by the destination peer.
When LQM is enabled, Link Quality Reports (LQRs) are sent, in place of keepalives, every keepalive period. All incoming keepalives are responded to properly. If LQM is not configured, keepalives are sent every keepalive period and all incoming LQRs are responded to with an LQR.
Note
To enable LQM on the interface, do the following while still in interface configuration mode:
Step 1
RPM-3(config-if)# ppp quality percentageThe percentage argument specifies the link quality threshold. That percentage must be maintained, or the link is deemed to be of poor quality and taken down.
Configuring the Switch Interface and PVCs
To configure the switch interface and the permanent virtual circuits (PVCs) to be used in conjunction with the MGX-RPM-1FE-CP back card, complete the following tasks:
Configuring the IP Address
No IP address should be associated with the switch interface. To configure no IP address, do the following:
Step 1
RPM-3# configure terminalEnter configuration commands, one per line. End with CNTL/Z.RPM-3(config)#Step 2
RPM-3(config)# interface switch numberStep 3
RPM-3(config-if)# no ip address
Configuring the PVC
To configure a PVC on a switch subinterface, do the following while still in interface configuration mode:
Step 1
RPM-3(config-if)# interface Switch number.subinterface point-to-pointStep 2
RPM-3(config-if)# pvc vpi/vciStep 3
RPM-3(config-if)# encapsulation aal5 encap [virtual-template number].
Saving the Configuration
Once you have completed the configuration, save the configuration by doing the following:
Step 1
Step 2
RPM-3# copy running-config startup-config
Verifying the Configuration of the MGX-RPM-1FE-CP Back Card
To verify the configuration of the PPP multiplexing and the cRTP/cUDP compression on the MGX-RPM-1FE-CP back card, enter the following command:
RPM-3# show running-configMonitoring and Managing the MGX-RPM-1FE-CP Back Card
You can use Cisco's network management applications, such as Cisco Works for Mobile Wireless (CW4MW), to monitor and manage aspects of the MGX-RPM-1FE-CP back card.
To enable remote network management of the MGX-RPM-1FE-CP back card, do the following:
Step 1
RPM-3# configure terminalEnter configuration commands, one per line. End with CNTL/Z.RPM-3(config)#Step 2
RPM-3(config)# ip host hostname ip_addressWhere hostname is the name assigned to the Operations and Maintenance (O&M) workstation and ip_address is the address of the network management workstation.
Step 3
RPM-3(config)# logging hostnameWhere hostname is the name assigned to the CW4MW workstation with the ip host command.
Step 4
RPM-3(config)# interface loopback numberRPM-3(config-if)# ip address ip_address subnet_maskStep 5
RPM-3(config-if)# exitStep 6
RPM-3(config)# snmp-server host hostname [traps | informs] [version {1 | 2c | 3 [auth | noauth | priv]}] community-string [udp-port port] [notification-type]Where hostname is the name assigned to the CW4MW workstation with the ip host command in Step 2.
Step 7
RPM-3(config)# snmp-server community public RORPM-3(config)# snmp-server community private RWStep 8
RPM-3(config)# snmp-server enable trapsStep 9
RPM-3(config)# snmp-server trap-source loopback numberWhere number is the number of the loopback interface you configured for the O&M in Step 4.
Step 10
Step 11
RPM-3# copy running-config startup-configTo monitor and maintain multilink and FE interfaces and to view information about the PPP mux and header compression configuration, use the following commands:
Command Reference
The following commands have been added or changed with this release:
The following commands were not altered but have been included for your convenience:
•
•
•
clear ip rtp header-compression
To clear Real-Time Transport Protocol (RTP) header compression structures and statistics, use the clear ip rtp header-compression EXEC command.
clear ip rtp header-compression [type number]
Syntax Description
Command Modes
EXEC
Command History
Usage Guidelines
If this command is used without an interface type and number, it clears all RTP header compression structures and statistics.
Examples
The following example clears RTP header compression structures and statistics for multilink interface 1:
clear ip rtp header-compression multilink 1Related Commands
clear ppp mux
To clear PPP mux statistics, use the clear ppp mux EXEC command.
clear ppp mux [interface interface]
Syntax Description
interface
(Optional) The identifier of the multilink interface for which you want to clear counters.
Defaults
If no interface is specified, statistics for all multilink interfaces are cleared.
Command Modes
EXEC
Command History
Usage Guidelines
None
Examples
The following example clears PPP mux statistics for multilink interface 1:
clear ppp mux interface multilink1Related Commands
ip rtp compression-connections
To specify the total number of Real-Time Transport Protocol (RTP) header compression connections that can exist on an interface, use the ip rtp compression-connections interface configuration command. To restore the default value, use the no form of this command.
ip rtp compression-connections number
no ip rtp compression-connections
Syntax Description
number
Number of RTP header compression connections the cache supports, in the range from 3 to 1000. The default is 16 connections.
Defaults
16 connections
Command Modes
Interface configuration
Command History
Examples
The following example changes the number of RTP header compression connections supported to 150 and suppresses IP ID checking during RTP compression when using Cisco IOS Release 12.3(11)T or later:
interface serial 0encapsulation pppip rtp header-compression ignore-idip rtp compression-connections 150Related Commands
ip rtp header-compression
Enables RTP header compression.
show ip rtp header-compression
Displays RTP header compression statistics.
ip rtp header-compression
To enable Real-Time Transport Protocol (RTP) header compression, use the ip rtp header-compression interface configuration command. To disable RTP header compression, use the no form of this command.
ip rtp header-compression [passive] [ignore-id]
no ip rtp header-compression [passive] [ignore-id]
Syntax Description
Defaults
Disabled
Command Modes
Interface configuration
Command History
Usage Guidelines
If you use this command without the passive keyword, the software compresses all RTP traffic.
You can compress IP/UDP/RTP headers or IP/UDP headers to reduce the size of your packets. Compressing headers is especially useful for RTP, because RTP payload size can be as small as 20 bytes, and the uncompressed header is 40 bytes.
RTP header compression is supported on serial lines using PPP encapsulation. You must enable compression on both ends of a serial connection.
Examples
The following example enables RTP header compression on Fast Ethernet interface 1, limits the number of RTP header compression connections to 10, and suppresses IP ID checking during RTP compression when using Cisco IOS Release 12.3(11)T and later:
interface serial 0encapsulation pppip rtp header-compression ignore-idip rtp compression-connections 10Related Commands
ppp mux
To enable PPP multiplexing/demultiplexing, use the ppp mux command in interface configuration mode. To disable PPP multiplexing/demultiplexing, use the no form of this command.
ppp mux
no ppp mux
Syntax Description
This command has no parameters.
Defaults
PPP multiplexing/demultiplexing is disabled by default.
Command Modes
Interface configuration
Command History
Examples
The following example enables PPP multiplexing/demultiplexing.
ppp muxRelated Commands
ppp mux delay
To set the maximum time the processor can wait before sending a superframe, use the ppp mux delay command in interface configuration mode. To set the maximum delay to the default, use the no form of this command.
ppp mux delay integer
no ppp mux delay
Syntax Description
integer
The maximum number of microseconds that the processor can wait before sending out a PPP superframe. Possible values are 0 through 4000000 microseconds.
Defaults
The default maximum delay is 800.
Command Modes
Interface configuration
Command History
Usage Guidelines
To use this command, you must first enable PPP multiplexing/demultiplexing.
When the ppp mux delay command is configured, the maximum number of microseconds that the processor can wait resolves to the nearest 200-microsecond increment. For example, if ppp mux delay 302 is specified, the actual maximum number of microseconds that the processor can wait before sending out a PPP superframe is 400. If ppp mux delay 298 is specified, the actual maximum number of microseconds that the processor can wait before sending out a PPP superframe is 200.
Examples
The following example sets the maximum delay to 200 microseconds.
ppp mux delay 200Related Commands
ppp mux frame
To set the maximum length (in bytes) of the PPP superframes, use the ppp mux frame command in interface configuration mode. To set the maximum length to the default, use the no form of this command.
ppp mux frame integer
no ppp mux frame
Syntax Description
integer
The maximum number of bytes in any multiplexed PPP superframe. Possible values are 0 through 512 bytes.
Defaults
The default maximum length is 197.
Command Modes
Interface configuration
Command History
Usage Guidelines
To use this command, you must first enable PPP multiplexing/demultiplexing.
Examples
The following example sets the maximum superframe length to 80 bytes.
ppp mux frame 80Related Commands
ppp mux pid
To set the default PPP protocol ID, use the ppp mux pid command in interface configuration mode. To remove this configuration, use the no form of this command.
ppp mux pid integer
no ppp mux pid
Syntax Description
Defaults
The default is 33 (0x21), which is the IP protocol.
Command Modes
Interface configuration
Command History
Usage Guidelines
To use this command, you must first enable PPP multiplexing/demultiplexing.
Examples
The following example sets the default PPP protocol ID to 8.
ppp mux pid 8Related Commands
ppp mux subframe length
To set the maximum length (in bytes) of the PPP subframes, use the ppp mux subframe length command in interface configuration mode. To set the maximum length to the default, use the no form of this command.
ppp mux subframe length integer
no ppp mux subframe length
Syntax Description
integer
The maximum number of bytes in any single subframe that is to be multiplexed. Possible values are 0 through 512 bytes.
Defaults
The default maximum length is 195.
Command Modes
Interface configuration
Command History
Usage Guidelines
To use this command, you must first enable PPP multiplexing/demultiplexing. The maximum length of the subframe should be the maximum length of the superframe minus the length of the L2 header.
Examples
The following example sets the maximum subframe length to 20 bytes.
ppp mux subframe length 20Related Commands
ppp mux subframe count
To set the maximum number of PPP subframes that can be contained in a superframe, use the ppp mux subframe count command in interface configuration mode. To set the maximum number to the default, use the no form of this command.
ppp mux subframe count integer
no ppp mux subframe count
Syntax Description
integer
The maximum number of subframes that can be contained in a superframe. Possible values are 0 through 15 bytes.
Defaults
The default maximum is 15.
Command Modes
Interface configuration
Command History
Usage Guidelines
To use this command, you must first enable PPP multiplexing/demultiplexing.
Examples
The following example sets the maximum subframe count to 20 bytes.
ppp mux subframe count 20Related Commands
show ip rtp header-compression
To show Real-Time Transport Protocol (RTP) header compression statistics, use the show ip rtp header-compression EXEC command.
show ip rtp header-compression [type number] [detail]
Syntax Description
Command Modes
EXEC
Command History
Usage Guidelines
The detail keyword is not available with the show ip rtp header-compression command on a Route Switch Processor (RSP). However, the detail keyword is available with the show ip rtp header-compression command on a Versatile Interface Processor (VIP). Enter the show ip rtp header-compression type number detail command on a VIP to retrieve detailed information regarding RTP header compression on a specific interface.
Examples
The following is sample output from the show ip rtp header-compression command:
show ip rtp header-compressionRTP/UDP/IP header compression statistics:Interface Virtual-Access1:Rcvd: 0 total, 0 compressed, 0 errors0 dropped, 0 buffer copies, 0 buffer failuresSent: 430 total, 429 compressed,15122 bytes saved, 139318 bytes sent1.10 efficiency improvement factorConnect:16 rx slots, 16 tx slots,0 long searches, 0 misses 0 collisions, 0 negative cache hits100% hit ratio, five minute miss rate 0 misses/sec, 0 maxInterface Virtual-Template15:Rcvd: 0 total, 0 compressed, 0 errors0 dropped, 0 buffer copies, 0 buffer failuresSent: 0 total, 0 compressed,0 bytes saved, 0 bytes sentConnect:16 rx slots, 16 tx slots,0 long searches, 0 misses 0 collisions, 0 negative cache hitsTable 2 describes the significant fields shown in the display.
Related Commands
show ppp mux
To display counters for a multilink interface on the MGX-RPM-1FE-CP back card, use the show ppp mux command in EXEC mode.
show ppp mux [interface interface]
Syntax Description
interface interface
(Optional) The identifier of the multilink interface for which you want to view counters.
Defaults
If no interface is specified, statistics for all multilink interfaces are displayed.
Command Modes
EXEC
Command History
Usage Guidelines
This command is only valid when issued against multilink or PPP interfaces.
Examples
The following is an example of the output generated by this command.
show ppp mux interface multilink 1PPP Multiplex Statistics on Interface Multilink1:Multiplex:Total input packets:0Errored input packets:0Valid input bytes:0Total output packets:0Multiplexed output packets:0Output bytes:0Efficiency improvement factor:0%Demultiplex:Total input packets:0Multiplexed input packets:0Errored input packets:0Valid input bytes:0Total output packets:0Output bytes:0Efficiency improvement factor:0%Table 3 describes the significant fields shown in the display.
The efficiency improvement factor is calculated as follows:
Multiplex efficiency improvement factor = 100 * (Total bytes saved) / (Total bytes received)
Where total bytes saved = bytes_received_at_muxer - bytes_sent_at_muxer.
Demultiplex efficiency improvement factor = 100 * (Total bytes saved) / (Total bytes sent)
Where total bytes saved = bytes_sent_at_demuxer - bytes_received_at_demuxer.
Related Commands
RJ-45 Pinout Configuration
Table 4 shows the pinout configuration of the RJ-45 connectors on the MGX-RPM-1FE-CP back card.
Table 4 RJ-45 Pinout
PIN
Description
1
transmit data +
2
transmit data -
3
receive data +
4
not used
5
not used
6
receive data -
7
not used
8
not used
Understanding the LEDs
The MGX-RPM-1FE-CP back cards contains an enabled LED, which is standard on all back cards, and two status LEDs.
After system initialization, the enabled LED goes on to indicate that the back card has been enabled for operation. The following conditions must be met before the enabled LED goes on:
•
•
•
If any of these conditions is not met, or if the initialization fails for other reasons, the enabled LED does not go on.
Following are the status LEDs for the FE port and an explanation of each:
•
•
Related Documentation
This following documents contain important information related to the MGX-RPM-1FE-CP back card:
•
•
Obtaining Documentation
The following sections provide sources for obtaining documentation from Cisco Systems.
World Wide Web
You can access the most current Cisco documentation on the World Wide Web at the following sites:
Ordering Documentation
Cisco documentation is available in the following ways:
•
http://www.cisco.com/cgi-bin/order/order_root.pl
•
http://www.cisco.com/go/subscription
•
Documentation Feedback
If you are reading Cisco product documentation on the World Wide Web, you can submit technical comments electronically. Click Feedback in the toolbar and select Documentation. After you complete the form, click Submit to send it to Cisco.
You can e-mail your comments to bug-doc@cisco.com.
To submit your comments by mail, use the response card behind the front cover of your document, or write to the following address:
Attn Document Resource Connection
Cisco Systems, Inc.
170 West Tasman Drive
San Jose, CA 95134-9883We appreciate your comments.
Obtaining Technical Assistance
Cisco provides Cisco.com as a starting point for all technical assistance. Customers and partners can obtain documentation, troubleshooting tips, and sample configurations from online tools. For Cisco.com registered users, additional troubleshooting tools are available from the TAC website.
Cisco.com
Cisco.com is the foundation of a suite of interactive, networked services that provides immediate, open access to Cisco information and resources at anytime, from anywhere in the world. This highly integrated Internet application is a powerful, easy-to-use tool for doing business with Cisco.
Cisco.com provides a broad range of features and services to help customers and partners streamline business processes and improve productivity. Through Cisco.com, you can find information about Cisco and our networking solutions, services, and programs. In addition, you can resolve technical issues with online technical support, download and test software packages, and order Cisco learning materials and merchandise. Valuable online skill assessment, training, and certification programs are also available.
Customers and partners can self-register on Cisco.com to obtain additional personalized information and services. Registered users can order products, check on the status of an order, access technical support, and view benefits specific to their relationships with Cisco.
To access Cisco.com, go to the following website:
Technical Assistance Center
The Cisco TAC website is available to all customers who need technical assistance with a Cisco product or technology that is under warranty or covered by a maintenance contract.
Contacting TAC by Using the Cisco TAC Website
If you have a priority level 3 (P3) or priority level 4 (P4) problem, contact TAC by going to the TAC website:
P3 and P4 level problems are defined as follows:
•
•
In each of the above cases, use the Cisco TAC website to quickly find answers to your questions.
To register for Cisco.com, go to the following website:
http://www.cisco.com/register/
If you cannot resolve your technical issue by using the TAC online resources, Cisco.com registered users can open a case online by using the TAC Case Open tool at the following website:
http://www.cisco.com/tac/caseopen
Contacting TAC by Telephone
If you have a priority level 1 (P1) or priority level 2 (P2) problem, contact TAC by telephone and immediately open a case. To obtain a directory of toll-free numbers for your country, go to the following website:
http://www.cisco.com/warp/public/687/Directory/DirTAC.shtml
P1 and P2 level problems are defined as follows:
•
•
