diff options
Diffstat (limited to '3rdparty/openpgm-svn-r1085/pgm/plan.txt')
| -rw-r--r-- | 3rdparty/openpgm-svn-r1085/pgm/plan.txt | 238 |
1 files changed, 238 insertions, 0 deletions
diff --git a/3rdparty/openpgm-svn-r1085/pgm/plan.txt b/3rdparty/openpgm-svn-r1085/pgm/plan.txt new file mode 100644 index 0000000..b1747ae --- /dev/null +++ b/3rdparty/openpgm-svn-r1085/pgm/plan.txt @@ -0,0 +1,238 @@ +pgmdump +------- + +View all packets like tcpdump, but updated to full spec and allow dump of payload. + + +pgmtop +------ + +Dump realtime packet statistics in a ncurses display, mix of top/htop/netop. + + +basic_send +---------- + +Send an ODATA packet and terminate. + +Accept string payload and network parameters on command line. + +Send to multicast or send to unicast AFI. + +IPv4/6. + +Define optional session start, late join tags. + + +spm_idle +-------- + +Idle in an event loop sending out SPM packets. + + +stream_send +----------- + +Send a constant stream of ODATA and SPM packets. + + +basic_http +---------- + +Simple embedded web server + + +basic_recv +---------- + +Listen to packets indicating data loss, view details through web interface. + + +basic_container +--------------- + +Test performance of glib containers for fast allocating for a dynamic transmit window. + + +basic_txw +--------- + +Test performance of a basic transmit window implementation. + + +nak_txw +------- + +Test performance of random access to packets inside the window. + + +stream_send_with_nak +-------------------- + +Respond to NAK's with RDATA. + + +basic_recv_with_nak +------------------- + +Listen to packets and send NAK's to rebuild data. + + +dumpif +------ + +Display all IP based interfaces and basic details. + + +testif +------ + +Test various combinations of network specification. + + +sw_calc +------- + +Basic calculation tests of wrap-around sliding windows and a leading edge. + + +basic_recv_with_rxw +------------------- + +Listen to packets buffered with a receive window. + + +test_cpu_timers +--------------- + +Calculate drift between processors, cores, and hyper-threads. + + +pgmsend +-------- + +basic_send updated to use transmit window. + + +pgmrecv +-------- + +basic_recv_with_rxw without web interface, primary displays messages from pgmsend. + + +syncrecv +-------- + +pgmrecv implemented outside GLib with a synchronous coding paradigm. + + +pgmping +------- + +Dual mode: one to send fixed messages like pgmsend and listen for response, two to listen for +messages and reply. + + +block_send +---------- + +Send APDUs over ODATA. + + +(pgmrecv can receive APDUs) + +test_rs +------- + +Test 8-bit symbol Reed Solomon encoding and decoding with errors & erasures. + +test_fec +-------- + +Test fec creation and recovery. + + +send_with_fec +-------------------- + +Send APDUs over ODATA with FEC. + + + +Scenarios to reproduce +********************** + +- Packet loss in stream causing NAK generation. +- Link saturation in sending causing API feedback. +- Link peak stable speed. +- Maxium NAK generation to determine NCF/RDATA throughput. +- Corrupt packets with invalid IP checksum (? generate IP HDR in sender) +- Corrupt packets with invalid PGM checksum. +- Invalid packet values. +- NAK to NCF latency. +- NAK to RDATA latency. +- Publish bandwidth: total, per packet type, payload, per recipient (?) +- Subscribe bandwidth: total, per packet type, payload, per publisher (?) +- Restarting a session with similar or dissimilar sequence numbering. + +Outstanding questions +********************* + +- Is it faster to use chunks containing multiple packets instead of one MTU + per packet. Does aligning with system page size matter? +- Can g_timers be dropped easily for gettimeofday and avoid floating point math? Possible + to pass timer upstream with contiguous data for easy access. +- Can time evaluation be dropped to at most once per main loop event? +- Does code work 32 bit and is it optimal? +- Should trash stacks be monitored and controlled externally? For example, clearing + up after bursts or administrative control. +- Should trash stacks have a upper limit to then free to the slice allocator? +- Should lost packets be managed as ranges or individual sequence numbers, how + does each method affect performance? + +* The initial draft of PGM included OPT_RANGE option for NAKs to specify a range of lost + packets, this was replaced in the final draft with NAK lists. Some research hints that + ranges are suitable: + + http://www.isoc.org/inet2001/CD_proceedings/T54/T54.htm + http://tools.ietf.org/html/draft-speakman-pgm-spec-01 + +- Are place holders necessary? Can state timeouts be managed without a per sequence number + object? For example by the next data object, or an extra object for an ncf extended window: + note that nak packet generation should easily dwarfs time spent unless advantage is taken + of the additional 62 naks in a opt_nak_list. Caution has to be taken with the cost of + splitting a range when a packet is inserted in the middle, although idealy it should + be sequential from the trailing edge. +- Is it better to have send sockets per transport, or shared, bound to each interface? +- Cost of sharing state helper lists between receive windows? On culling a peer the lists + have to be purged. Saves iterating the hash list of receivers. +- Encapsulated UDP lists two ports, 3305 for broadcast, 3306 for unicast, how is this + supposed to map to regular PGM, and why the split? + +Basic TODO list +*************** + +- Ensure standardised error handling and status reporting. +- Implement mechanism for data-loss feedback. +- OPT_SYN & OPT_FIN on sending side. +- Shared trash stacks between multiple receive windows (contexts). +- Shared trash stacks between transmit and receive windows. +- FEC: compatibility with SmartPGM FEC, MS FEC? +- NAK backoff learning. +- Full conformance testing. (nak backoffs remaining) +- Unit testing. +- System testing with valgrind. +- Performance testing with oprofile. +- Basic DLR. +- Implement PGM sender (only) support thread? +- eventfd instead of pipes for recent Linux kernels. + +Optionals +********* + +- Some form of broadcast statistics for passive monitoring. +- (fix) BCH Reed-Solomon codec as possibly faster alternative, albeit incompatible with Microsoft. +- Recommendations as per the RMT working group of the IETF for AL-FEC codecs: Raptor codes, LDPC- + staircase and LDPC-triangle codes. +- XDR based messaging format as example of binary encoded messaging. + |