Comment savoir si la compression PPP est activée pour le modem?

J'utilise Debian Linux sur un système embarqué, nous utilisons ppp pour nous connecter au WAN via un modem CDMA. Je veux savoir si la compression est utilisée par ppp .

Dans mes /var/log/messages je vois la ligne:

 kernel: [ 54.740000] PPP Deflate Compression module registered 

mais dans /var/log/debug je vois ceci:

 pppd[2433]: Protocol-Reject for 'Compression Control Protocol' (0x80fd) received 

La sortie de pppstats -z est:

 IN: COMPRESSED INCOMPRESSIBLE COMP | OUT: COMPRESSED INCOMPRESSIBLE COMP BYTE PACK BYTE PACK RATIO | BYTE PACK BYTE PACK RATIO 0 0 0 0 0.00 | 0 0 0 0 0.00 

La compression moyenne ci-dessus est-elle activée ou non?

Je crois que vous pouvez utiliser la command ppstats -z pour afficher les statistics de compression. S'il affiche tous les zéros, la compression n'est pas activée.

extrait de la page man

  -z Instead of the standard display, show statistics indicating the performance of the packet compression algorithm in use. When the -z option is specified, instead displays the following fields, relating to the packet compression algorithm currently in use. If packet compression is not in use, these fields will all display zeroes. The fields displayed on the input side are: COMPRESSED BYTE The number of bytes of compressed packets received. COMPRESSED PACK The number of compressed packets received. INCOMPRESSIBLE BYTE The number of bytes of incompressible packets (that is, those which were transmitted in uncompressed form) received. INCOMPRESSIBLE PACK The number of incompressible packets received. COMP RATIO The recent compression ratio for incoming packets, defined as the uncompressed size divided by the compressed size (including both compressible and incompressible packets). The fields displayed on the output side are: COMPRESSED BYTE The number of bytes of compressed packets transmitted. COMPRESSED PACK The number of compressed packets transmitted. INCOMPRESSIBLE BYTE The number of bytes of incompressible packets transmitted (that is, those which were transmitted in uncompressed form). INCOMPRESSIBLE PACK The number of incompressible packets transmitted. COMP RATIO The recent compression ratio for outgoing packets. 

Vérifiez /etc/ppp/options .

NE PAS éditer ce file, mais plutôt le copyr dans un location et le modifier.

vérifie ça:

 # Disable Address/Control compression negotiation (use default, ie # address/control field disabled). #-ac 

Plus d'infos vous pouvez find ici dans le PPP-HOWTO .