Bundles (NNCP)

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Bundles ¶

Usual nncp-xfer command requires filesystem it can operate on. That presumes random access media storage usage, like hard drives, USB flash drives and similar. But media like CD-ROM and especially tape drives are sequential by nature. You can prepare intermediate directory for recording to CD-ROM disc/tape, but that requires additional storage and is inconvenient.

Bundles, created with nncp-bundle command are convenient alternative to ordinary nncp-xfer. Bundle is just a collection of encrypted packets, stream of packets. It could be sequentially streamed for recording and digested back.

They do not require intermediate storage before recording on either CD-ROM or tape drive.

$ nncp-bundle -tx SOMENODE | cdrecord -tao -         # record directly to CD
$ nncp-bundle -tx SOMENODE | dd of=/dev/sa0 bs=10240 # record directly to tape

$ dd if=/dev/cd0 bs=2048 | nncp-bundle -rx  # read directly from CD
$ dd if=/dev/sa0 bs=10240 | nncp-bundle -rx # read directly from tape

They do not require filesystem existence to deal with, simplifying administration when operating in heterogeneous systems with varying filesystems. No mount/umount, zpool import/zpool export and struggling with file permissions.
```
$ nncp-bundle -tx SOMENODE | dd of=/dev/da0 bs=1M # record directly to
                                                  # hard/flash drive
$ dd if=/dev/da0 bs=1M | nncp-bundle -rx # read directly from drive
```
This is the fastest way to record outbound packets for offline transmission – sequential write is always faster, when no metainformation needs to be updated.
This is convenient to use with append-only storages, just sending/appending new bundles.
Bundles could be repeatedly broadcasted in one-way transmission. Sync protocol requires interactive connection, but bundles can contain mix of various recipients.

Technically bundle is valid POSIX.1-2001 pax archive with directory/files hierarchy identical to that is used in nncp-xfer: NNCP/RECIPIENT/SENDER/PACKET. So bundle can also be created by manual tar-ing of nncp-xfer resulting directory.