logon

Logon

Table of content

• Logon
  • OpenSAND Exploitation
  • OpenSAND Software Design
    • Logon Request (T_DVB_LOGON_REQ)
    • Logon Response (T_DVB_LOGON_RESP)
    • Logoff (T_DVB_LOGOFF)

Logon/Logoff messages are implemented in OpenSAND in order to signal the Gateways when a new terminal is in the system, so that the corresponding allocations be performed.

The logon procedure for a ST has four steps:

• Upon initalization, the ST sends the Logon request towards the satellite on a dedicated carrier.
• The SAT redirects the Logon request towards the corresponding gateway on a dedicated carrier.
• After receiving the Logon request, the GW sends the Logon response towards the satellite one a dedicated carrier.
• The SAT broadcasts the Logon response to all terminals on the same spot as the destination terminal.

When a Gateway receives the Logon request from a terminal, it allocates the necessary resources to the terminal, and answers with the allocated terminal ID if the login is successful.

The LogOff procedure allows to inform the Gateways that a terminal will no longer be present (so that no resource allocations be made). However, it is not currently implemented in OpenSAND for terminals (it is only implemented for simulated terminals).

In OpenSAND Logon/Logoff messages are not affected by attenuation, so they will never be lost.

OpenSAND Exploitation

These features are transparent to the user, and no configuration is needed.

No probes exist associated to signaling messages, although some logs are emitted when a certain type of signaling message has been received/emitted.

OpenSAND Software Design

Log-in and Log-off messages are implemented as specializations of the DvbFrameTpl (which means that each type of message has different header fields).

The implemented message types, along with the header fields are:

Logon Request (T_DVB_LOGON_REQ)

Header fields:

• mac: the terminal ID.
• rt_bandwidth: the real time fixed bandwidth in kbits/s.
• max_rbdc: the maximum RBDC value in kbits/s.
• max_vbdc: the maximum VBDC value in kbits/s.
• is_scpc: the terminal is SPOC.

The class LogonRequest implements methods for initializing and working with DvbFrames of this type.

This packet is generated by the BlockDvbTal right after all the blocks have been initialized, and is sent to the gateway.

Logon Response (T_DVB_LOGON_RESP)

Header fields:

• mac: the terminal ID.
• group_id: the assigned group ID.
• logon_id: the assigned logon ID.

The class LogonResponse implements methods for initializing and working with DvbFrames of this type.

This packet is generated by the BlockDvbNcc after receiving a LogonRequest from a terminal, and is sent to the same terminal.

Logoff (T_DVB_LOGOFF)

Header fields:

• mac: the terminal ID.

The class Logoff implements methods for initializing and working with DvbFrames of this type.

This message should be generated by the BlockDvbTal when terminating. However, it is only implemented by simulation terminals.