Chapter 1 Introduction

IPmux-1/1EInstallation and Operation Manual

 

 

The maximum Ethernet throughput in dynamic CAS mode is calculated by:

[( payload8000 ) x ((payload+ 4) x TS) + 4 + frame overhead] x 8 bits

where frame overhead is 46 bytes, including MAC, LLC, IP, and UFP layers

where TS = number of configured time slots

where payload = number of active time slot bytes per frame (24 to 64)

Note

 

The frame overhead does not include:

 

 

Preamble field: 7 bytes

 

SFD field: 1 byte

 

Interframe gap: 12 bytes

 

VLAN field (when used): 4 bytes.

 

 

Ethernet Throughput in CESoIP Mode

Configuring the packet delay and the number of time slots controls the Ethernet throughput. The range of the packet delay is 3 to 127 msec.

A large number of time slots and a long packet delay can surpass the maximum Ethernet frame size.

The maximum Ethernet throughput in CESoIP mode is calculated by:

[(

1000

) x ((

packet delay

) x TS) + 12 + frame overhead] x 8 bits

packet delay

 

 

8

 

where frame overhead is 46 bytes, including MAC, LLC, IP, and UFP layers

where TS = number of configured time slots:

for an unframed E1 interface = 32 for an unframed E1 interface = 24

where packet delay = 3 to 127.

Round Trip Delay

The voice path round-trip delay is a function of all connections and network parameters. The calculation for E1/T1 in each connection mode is described in the following sections.

1-22

Functional Description

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Cisco Systems IPMUX-1E Round Trip Delay, Ethernet Throughput in CESoIP Mode, Frame overhead does not include