RAD Data comm IPmux-11 Manuel D’Utilisation

Installation and Operation Manual 

Chapter 1  Introduction 

IPmux-11 Ver. 2.00 

Functional Description 

1-13 

Configuring the TDM bytes per frame (TDM bytes/frame) parameter has impact on 
the Ethernet throughput (bandwidth or traffic traveling through the Ethernet). This 
parameter controls the number of TDM bytes encapsulated in one frame.  
The TDM bytes/frame parameter can be configured to N × 48 bytes where N is an 

integer between 1 and 30.  

 

To calculate Ethernet throughput as a function of TDM bytes/frame: 
Ethernet load (bps) = [(frame overhead (bytes) + TDM bytes/frame) × 8] × 

frames/second 
Frame overhead = Ethernet overhead + IP overhead = 46 bytes 

 

The frame overhead does not include:  
•  Preamble field: 7 bytes 
•  SFD field: 1 byte 
•  Interframe gap: 12 bytes 
•  VLAN field (when used): 4 bytes. 

 

Frame/second = 

Unframed: 5447/n for a full E1 

  

    4107/n for a full T1 

 

 Framed: 8000 

× k/(46.875 x n) 

Where k = number of assigned timeslots 

Where n = 

48

e

bytes/fram

TDM

 

The maximum Ethernet throughput mode is calculated by: 

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