Remote#

Remote#

Remote#wr t

Building configuration...

Current configuration:

!

version 11.3

no service pad

Extended Super Frame and Binary Eight Zero Substitution are the framing/linecoding that most T1s will use. You will have to ask your phone company what frame type and linecode your line is using.

The channel-group is used to define which of the 24 possible DS0s the router will use. The possible values of the channel-group are 0-23 and it doesn't matter which number is used. If you don't define a channel-group no data or voice will be sent out the MFT. You may use any part of the 24 timeslots. Remember to include the speed 64 part of the command. The controller requires a full T1/E1 signal in order to be active.

It does support fragmented T1/E1 lines. The DS0s that are used when the MC3810 is attached to a fragmented T1/E1 are defined using the channel-group command. Examples for a 512K line:

The channel-group defines the DS0s that interface Serial 2 will use. The T1/E1 specific commands are put under the controller and the layer 2 and 3 commands are configured under the Serial 2 interface. Since the channel-group uses the Serial 2 interface it isn't possible to define more than one channel-group. Other channelized T1/E1 cards on different routers, such as the 3600 series, allow the configuration of multiple channel-groups. Therefore, it isn’t possible to configure the MC3810 for multiple point to point leased lines to multiple remote sites. The MC3810 doesn't have this feature and there aren't any plans at this time to add the ability to configure multiple channel-groups.

This command is automatically added when you enter the voice-encap command. Voice packets always have priority over data packets so none of the more sophisticated queuing mechanisms can be used. The queuing is voice packets first and FIFO for all other packets.

This is a major difference in the configuration of the MC3810. Usually when the frame-relay map command is used the interface-dlci command isn’t needed. The MC3810 uses this command to define the size of the data packets. Even though the command is "voice-encap", it is defining the size that the data packets will be fragmented into using the Frame Relay Forum’s specification number 12 for data fragmentation over Frame Relay. It is most commonly referred to as FRF.12. Other Cisco routers don’t support FRF.12 currently and will not be able to pass data with a MC3810 that is using this type of fragmentation. Compliance to FRF.12 will be added in the 12.x version of software for the other routers.

The voice-encap size is determined by the speed of the pipe that is being used. In this sample configuration the entire 24 channels of the T1 are being used so the size is 1500 bytes which is the largest packet size that an ethernet interface will send into the router. When the encap size is 1500, no fragmentation is being done by the MC3810. The fragmentation size is 80 bytes per 64K of bandwidth so a 256K pipe would have a voice-encap size of 320. The data is fragmented so a large data packet will not delay a voice packet when using smaller bandwidth pipes.

The class sample is the name of the frame relay map-class that is used to define traffic shaping. Traffic shaping must be defined when transporting voice over frame relay. If traffic shaping isn’t defined the router will send packets to the frame relay cloud at the clock speed of the line. If the traffic is sent at a higher rate than the CIR packets will be delayed and perhaps even dropped. While TCP/IP will resend data, delaying or dropping voice packets will effect the voice quality.

The hold-queue size is increased to 1024 in order to allow more buffers for the fragmentation of data packets and holding them in the queue while voice packets are being sent out of the interface. The command is automatically added when the interface is configured for voice.

The map-class frame-relay is where the traffic shaping parameters are configured. The name used, sample, was defined under the serial interface with the "class sample" command. Multiple map-classes may be configured and more than one interface-dlci can use the same map-class. If different DLCIs have a different CIR then multiple map-classes will be needed.

The default when the map-class is created is to not do adaptive-shaping. If you want to turn it on the options are BECN and Foresight.

The Committed Information Rate is set to 128K. The CIR is determined when the frame relay service is ordered. It is the amount of bandwidth that the frame relay provider guarantees.

These are the analog ports. Only 2 analog cards are in this MC3810. Commands specific to the port are entered under the voice-port.