Avaya Configuring Data Compression Services Manuel d'utilisateur télécharger pdf (Page 22)

Configuring Data Compression Services

1-4

Hardware Compression Contexts

context

refers to compression and decompression for a single VC. Compression

hardware maps a context to speciﬁc regions of compression and decompression

memory. If you have a 32-context compression daughterboard, you can

simultaneously run compression over 31 continuous packet compression (CPC)

contexts, each using an 8 KB history size, with one shared 8 KB packet-by-packet

(PPC) context. If you have a 128-context compression daughterboard, you can

simultaneously run compression over 127 CPC contexts, each using an 8 KB

history size, with one shared 8 KB PPC context. For more information on CPC

and PPC, see the section, “Compression Mode,” later in this chapter.

The only difference between the two Bay Networks compression daughterboards

is that the 128-context daughterboard has more memory

(2 MB compression/1 MB decompression, as opposed to 512 KB compression/

256 KB decompression for the 32-context daughterboard).

For more information, see the section, “History Size,” later in this chapter.

How Data Compression Works

The following sections describe how Bay Networks data compression works. As

you read these sections, refer to Figure 1-1, which illustrates CCP and WCP

initialization on a PPP link.

Note:

If you conﬁgure more VCs for hardware compression than your

daughterboard can support, you have no way of controlling which VCs will in

fact use hardware compression. You should plan your network to use hardware

compression on the VCs most important to you within the limits of your

equipment. By default, all VCs that exceed the hardware context limit use

software compression.

1 2 ... 17 18 19 20 21 22 23 24 25 26 27 ... 51 52

Pas de commentaire

Avaya Configuring Data Compression Services Manuel d'utilisateur Page 22