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[doc] batman-adv-doc,master: minor fixes (38989eda)
by postmaster＠open-mesh.org 14 Dec '17

14 Dec '17

Repository : ssh://git@open-mesh.org/doc On branches: batman-adv-doc,master >--------------------------------------------------------------- commit 38989eda48173d5437f9f14ae6238bfe33d43296 Author: Marek Lindner <lindner_marek(a)yahoo.de> Date: Fri Jan 2 12:37:04 2009 +0100 minor fixes >--------------------------------------------------------------- 38989eda48173d5437f9f14ae6238bfe33d43296 batman_iv.docbook | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/batman_iv.docbook b/batman_iv.docbook index 2abbce83..6e565986 100644 --- a/batman_iv.docbook +++ b/batman_iv.docbook @@ -300,10 +300,10 @@ TODO Explain multiple interfaces, which interface sends which OGM by which TTL, <textobject> <phrase>packet hops</phrase> </textobject> </inlinemediaobject> - B.A.T.M.A.N. III would have dropped the packet at this point. It has a duplicate packet detection based on sequence numbers. The sequence number is known, hence the packet dropped (the fastest packet wins). In asymetric environments this may lead to suboptimal routing decisions. Therefore B.A.T.M.A.N. IV interprets the arrival of this packet as second path towards the originator. This path transmits the packet slower (due to more hops for example) but but may offer a better transmit quality. + B.A.T.M.A.N. III would have dropped the packet at this point. It has a duplicate packet detection based on sequence numbers only. The sequence number is known, hence the packet dropped (the fastest packet wins). In asymetric environments this may lead to suboptimal routing decisions. Therefore B.A.T.M.A.N. IV interprets the arrival of this packet as second path towards the originator. This path transmits the packet slower (due to more hops for example) but but may offer a better transmit quality. Duplicate sequence numbers are dropped if they arrive via the same neighbor. </para> <para> - On a lossy medium the TQ value is decreased while travelling from hop to hop (see asymetric link handling). The Ethernet connection does not suffer from packet loss which results in not decreasing the TQ value at all. Node A has 2 possible routes towards the originator: The node S itself and node B (both will advertise the same TQ value). [bild3] + On a lossy medium the TQ value is decreased while travelling from hop to hop (see asymetric link handling). The Ethernet connection does not suffer from packet loss which results in not decreasing the TQ value at all. Node A has 2 possible routes towards the originator: The node S itself and node B (both will advertise the same TQ value). <inlinemediaobject> <imageobject> <imagedata fileref="images/hop_penalty5.pdf" format="EPS" scale="50" /> </imageobject> <imageobject> <imagedata fileref="images/hop_penalty5.png" format="PNG" /> </imageobject>

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[doc] batman-adv-doc, master: change SOURCE to S in pictures (c010bb16)
by postmaster＠open-mesh.org 14 Dec '17

14 Dec '17

Repository : ssh://git@open-mesh.org/doc On branches: batman-adv-doc,master >--------------------------------------------------------------- commit c010bb166ae3c726d49d3d75ed14e8641e04443a Author: Simon Wunderlich <siwu(a)hrz.tu-chemnitz.de> Date: Fri Jan 2 12:28:59 2009 +0100 change SOURCE to S in pictures >--------------------------------------------------------------- c010bb166ae3c726d49d3d75ed14e8641e04443a images/hop_penalty3.dia | Bin 1297 -> 1269 bytes images/hop_penalty4.dia | Bin 1448 -> 1414 bytes images/hop_penalty5.dia | Bin 1328 -> 1305 bytes images/hop_penalty6.dia | Bin 1453 -> 1419 bytes 4 files changed, 0 insertions(+), 0 deletions(-) diff --git a/images/hop_penalty3.dia b/images/hop_penalty3.dia index 26672e09..4ae03a75 100644 Binary files a/images/hop_penalty3.dia and b/images/hop_penalty3.dia differ diff --git a/images/hop_penalty4.dia b/images/hop_penalty4.dia index 5f093c01..ef16f62d 100644 Binary files a/images/hop_penalty4.dia and b/images/hop_penalty4.dia differ diff --git a/images/hop_penalty5.dia b/images/hop_penalty5.dia index 0e8d83a8..6cfe134e 100644 Binary files a/images/hop_penalty5.dia and b/images/hop_penalty5.dia differ diff --git a/images/hop_penalty6.dia b/images/hop_penalty6.dia index e002f695..281ca186 100644 Binary files a/images/hop_penalty6.dia and b/images/hop_penalty6.dia differ

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[doc] batman-adv-doc, master: add target to compile batman_iv part only (84e61f83)
by postmaster＠open-mesh.org 14 Dec '17

14 Dec '17

Repository : ssh://git@open-mesh.org/doc On branches: batman-adv-doc,master >--------------------------------------------------------------- commit 84e61f83107f4cb494f3d235cb4a4ed29063a0de Author: Simon Wunderlich <siwu(a)hrz.tu-chemnitz.de> Date: Sat Jan 3 15:35:16 2009 +0100 add target to compile batman_iv part only >--------------------------------------------------------------- 84e61f83107f4cb494f3d235cb4a4ed29063a0de Makefile | 4 ++++ batman.docbook => batman_iv_only.docbook | 4 ---- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/Makefile b/Makefile index 09946e1e..b8cac436 100644 --- a/Makefile +++ b/Makefile @@ -4,6 +4,10 @@ all: batman_doc batman_doc: Makefile *.docbook images docbook2html batman.docbook docbook2pdf batman.docbook +batman_iv_only_doc: Makefile *.docbook images + docbook2html batman_iv_only.docbook + docbook2pdf batman_iv_only.docbook + images: make -C images/ clean: diff --git a/batman.docbook b/batman_iv_only.docbook similarity index 89% copy from batman.docbook copy to batman_iv_only.docbook index d3382aad..595da8c3 100644 --- a/batman.docbook +++ b/batman_iv_only.docbook @@ -9,11 +9,7 @@ <book id="batman_book" lang="en"> -&bookinfo; -&introduction; &batman_iv; -&batman_adv; -&usage; </book>

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[doc] batman-adv-doc, master: TQ propagation update + echo cancellation (71ab9edf)
by postmaster＠open-mesh.org 14 Dec '17

14 Dec '17

Repository : ssh://git@open-mesh.org/doc On branches: batman-adv-doc,master >--------------------------------------------------------------- commit 71ab9edfa08abed964578dd3472ea8fd96c1b305 Author: Marek Lindner <lindner_marek(a)yahoo.de> Date: Mon Jan 5 20:57:50 2009 +0100 TQ propagation update + echo cancellation >--------------------------------------------------------------- 71ab9edfa08abed964578dd3472ea8fd96c1b305 batman_iv.docbook | 139 +++++++++++++++++++++++++++++++++++------------------- 1 file changed, 90 insertions(+), 49 deletions(-) diff --git a/batman_iv.docbook b/batman_iv.docbook index 6e565986..1656017f 100644 --- a/batman_iv.docbook +++ b/batman_iv.docbook @@ -156,46 +156,57 @@ TODO Explain multiple interfaces, which interface sends which OGM by which TTL, </para> <para> As explained in the previous section the packet counting floods the network with receiving link quality rather than transmit link quality. On the link-local level the transmit link quality can be derived from the receiving link quality by applying some calculations on the packet count. - +</para> +<para> <orderedlist> <listitem> - <para>B.A.T.M.A.N. knows the receiving link quality (RQ) by counting the packets of its neighbors.</para> <para> - <inlinemediaobject> - <imageobject> <imagedata fileref="images/rq.pdf" format="EPS" scale="50" /> </imageobject> - <imageobject> <imagedata fileref="images/rq.png" format="PNG" /> </imageobject> - <textobject> <phrase>Receive Quality (RQ)</phrase> </textobject> - </inlinemediaobject></para> + B.A.T.M.A.N. knows the receiving link quality (RQ) by counting the packets of its neighbors. + </para> + <para> + <inlinemediaobject> + <imageobject> <imagedata fileref="images/rq.pdf" format="EPS" scale="50" /> </imageobject> + <imageobject> <imagedata fileref="images/rq.png" format="PNG" /> </imageobject> + <textobject> <phrase>Receive Quality (RQ)</phrase> </textobject> + </inlinemediaobject> + </para> </listitem> <listitem> - <para>B.A.T.M.A.N. knows the echo link quality (EQ) by counting rebroadcasts of its own OGMs from his neighbors.</para> <para> - <inlinemediaobject> - <imageobject> <imagedata fileref="images/eq_alt1.pdf" format="EPS" scale="50" /> </imageobject> - <imageobject> <imagedata fileref="images/eq_alt1.png" format="PNG" /> </imageobject> - <textobject> <phrase>Echo Link Quality (EQ)</phrase> </textobject> - </inlinemediaobject></para> + B.A.T.M.A.N. knows the echo link quality (EQ) by counting rebroadcasts of its own OGMs from his neighbors. + </para> + <para> + <inlinemediaobject> + <imageobject> <imagedata fileref="images/eq_alt1.pdf" format="EPS" scale="50" /> </imageobject> + <imageobject> <imagedata fileref="images/eq_alt1.png" format="PNG" /> </imageobject> + <textobject> <phrase>Echo Link Quality (EQ)</phrase> </textobject> + </inlinemediaobject> + </para> </listitem> <listitem> - <para>B.A.T.M.A.N. can calculate the transmit link quality (TQ) by dividing the echo link quality by the receiving link quality.</para> <para> - <inlinemediaobject> - <imageobject> <imagedata fileref="images/tq.pdf" format="EPS" scale="50" /> </imageobject> - <imageobject> <imagedata fileref="images/tq.png" format="PNG" /> </imageobject> - <textobject> <phrase>Transmit Link Quality (TQ)</phrase> </textobject> - </inlinemediaobject></para> + B.A.T.M.A.N. can calculate the transmit link quality (TQ) by dividing the echo link quality by the receiving link quality. + </para> <para> - <inlinemediaobject> - <imageobject> <imagedata fileref="images/compute_tq.pdf" format="EPS"/> </imageobject> - <imageobject> <imagedata fileref="images/compute_tq.png" format="PNG" /> </imageobject> - <textobject> <phrase>compute the Transmit Link Quality</phrase> </textobject> - </inlinemediaobject> + <inlinemediaobject> + <imageobject> <imagedata fileref="images/tq.pdf" format="EPS" scale="50" /> </imageobject> + <imageobject> <imagedata fileref="images/tq.png" format="PNG" /> </imageobject> + <textobject> <phrase>Transmit Link Quality (TQ)</phrase> </textobject> + </inlinemediaobject> + </para> + <para> + <inlinemediaobject> + <imageobject> <imagedata fileref="images/compute_tq.pdf" format="EPS"/> </imageobject> + <imageobject> <imagedata fileref="images/compute_tq.png" format="PNG" /> </imageobject> + <textobject> <phrase>compute the Transmit Link Quality</phrase> </textobject> + </inlinemediaobject> </para> - </listitem> </orderedlist> - This shows that B.A.T.M.A.N. IV is able to compute the local Transmit Quality by using the same - mechanisms as B.A.T.M.A.N. III without adding further overhead. +</para> +<para> + This shows that B.A.T.M.A.N. IV is able to compute the local Transmit Quality by using the same + mechanisms as B.A.T.M.A.N. III without adding further overhead. </para> </sect2> <sect2 id="batman4_tq_prop"> @@ -222,8 +233,18 @@ TODO Explain multiple interfaces, which interface sends which OGM by which TTL, <imageobject> <imagedata fileref="images/tq_prop.png" format="PNG" /> </imageobject> <textobject> <phrase>TQ propagation</phrase> </textobject> </inlinemediaobject> - - +</para> +<para> + B.A.T.M.A.N. IV can not always rebroadcast the newly calculated TQ that came with the latest OGM. Instead the TQ that was received via the best neighbor is rebroadcasted to support asymetric link scenarios better. +</para> +<para> + Example: Node A and B are neighbors. Node A has a good connection towards node B but not vice versa. The node C has a good connection towards node A, has a good receiving link quality and bad sending quality towards B. [bild1] +</para> +<para> + Due to this layout the originator messages from node A have a good chance arriving at B but the TQ value propagated by node B is very low due to the high packet loss towards node A. The messages from node A that travel via node C have a low probablity arriving at node B due to the packet loss towards node B but have a much better TQ value. Node B will propagate many messages with a low TQ value (received from node A directly) and a few messages with a high TQ value (received from node A via node C) although the connection towards node A is very good. [bild2] +</para> +<para> + Therefore, B.A.T.M.A.N. IV will rebroadcast the received OGM with the TQ value of the best neighbor towards the originator. In the given example node B will place the TQ value received via node C in the message from node A before rebroadcasting it. It will flood its best TQ only. [bild3] </para> </sect2> @@ -250,31 +271,31 @@ TODO Explain multiple interfaces, which interface sends which OGM by which TTL, Although the transmit link quality is most important decision factor B.A.T.M.A.N. IV also keeps track of the receiving link quality. On the WiFi layer every unicast packet has to be acknowledged by the neighbor node to approve the transmission. If this neighbor is not able to sucessfully send his ACKs the WiFi layer considers this transmission to be failed and tries to retransmit until it gives up. </para> <para> - <inlinemediaobject> - <imageobject> <imagedata fileref="images/asym_link1.pdf" format="EPS" scale="50" /> </imageobject> - <imageobject> <imagedata fileref="images/asym_link1.png" format="PNG" scale="50" /> </imageobject> - <textobject> <phrase>Asymetry situation without asymetry penalty</phrase> </textobject> - </inlinemediaobject> + <inlinemediaobject> + <imageobject> <imagedata fileref="images/asym_link1.pdf" format="EPS" scale="50" /> </imageobject> + <imageobject> <imagedata fileref="images/asym_link1.png" format="PNG" scale="50" /> </imageobject> + <textobject> <phrase>Asymetry situation without asymetry penalty</phrase> </textobject> + </inlinemediaobject> </para> <para> Thus B.A.T.M.A.N. IV needs to penalize links that have have a poor receiving link quality. To avoid a simple hysteresis which completely turns on or off a link B.A.T.M.A.N. IV uses a mathematical function to give the receiving link quality stronger negative impact the weaker the link becomes. </para> <para> - <inlinemediaobject> - <imageobject> <imagedata fileref="images/asym_penalty.pdf" format="EPS" /> </imageobject> - <imageobject> <imagedata fileref="images/asym_penalty.png" format="PNG" /> </imageobject> - <textobject> <phrase>graph for asymetry penalty</phrase> </textobject> - </inlinemediaobject> + <inlinemediaobject> + <imageobject> <imagedata fileref="images/asym_penalty.pdf" format="EPS" /> </imageobject> + <imageobject> <imagedata fileref="images/asym_penalty.png" format="PNG" /> </imageobject> + <textobject> <phrase>graph for asymetry penalty</phrase> </textobject> + </inlinemediaobject> </para> <para> This obtained value is calculated into the TQ before it gets rebroadcasted. Neighboring nodes can weight the routing decision based on this information. In some situations the weak link is the only link available, so you want to use it, whereas in other cases better connections may exist. </para> <para> - <inlinemediaobject> - <imageobject> <imagedata fileref="images/asym_link2.pdf" format="EPS" scale="50" /> </imageobject> - <imageobject> <imagedata fileref="images/asym_link2.png" format="PNG" /> </imageobject> - <textobject> <phrase>Asymetry situation with applied asymetry penalty</phrase> </textobject> - </inlinemediaobject> + <inlinemediaobject> + <imageobject> <imagedata fileref="images/asym_link2.pdf" format="EPS" scale="50" /> </imageobject> + <imageobject> <imagedata fileref="images/asym_link2.png" format="PNG" /> </imageobject> + <textobject> <phrase>Asymetry situation with applied asymetry penalty</phrase> </textobject> + </inlinemediaobject> </para> </sect2> @@ -285,36 +306,44 @@ TODO Explain multiple interfaces, which interface sends which OGM by which TTL, </para> <para> Example topology: The node S (source) has a WiFi connection towards node A but no link to node B at all. Node A and node B are connected via Ethernet. We assume the Ethernet connection to be perfect (no packet loss) whereas the WiFi connection suffers from occasional collisions and interferences. +</para> +<para> <inlinemediaobject> <imageobject> <imagedata fileref="images/hop_penalty3.pdf" format="EPS" scale="50" /> </imageobject> <imageobject> <imagedata fileref="images/hop_penalty3.png" format="PNG" /> </imageobject> <textobject> <phrase>example topology</phrase> </textobject> </inlinemediaobject> - </para> <para> Whenever node A receives a packet via the WiFi connection it will rebroadcast the information on the Ethernet to inform neighbor nodes about the existance of the source node. Node B receives the broadcast and parses the packet before rebroadcasting it. At that point node A will receive that very packet again. +</para> +<para> <inlinemediaobject> <imageobject> <imagedata fileref="images/hop_penalty4.pdf" format="EPS" scale="50" /> </imageobject> <imageobject> <imagedata fileref="images/hop_penalty4.png" format="PNG" /> </imageobject> <textobject> <phrase>packet hops</phrase> </textobject> </inlinemediaobject> - +</para> +<para> B.A.T.M.A.N. III would have dropped the packet at this point. It has a duplicate packet detection based on sequence numbers only. The sequence number is known, hence the packet dropped (the fastest packet wins). In asymetric environments this may lead to suboptimal routing decisions. Therefore B.A.T.M.A.N. IV interprets the arrival of this packet as second path towards the originator. This path transmits the packet slower (due to more hops for example) but but may offer a better transmit quality. Duplicate sequence numbers are dropped if they arrive via the same neighbor. </para> <para> On a lossy medium the TQ value is decreased while travelling from hop to hop (see asymetric link handling). The Ethernet connection does not suffer from packet loss which results in not decreasing the TQ value at all. Node A has 2 possible routes towards the originator: The node S itself and node B (both will advertise the same TQ value). +</para> +<para> <inlinemediaobject> <imageobject> <imagedata fileref="images/hop_penalty5.pdf" format="EPS" scale="50" /> </imageobject> <imageobject> <imagedata fileref="images/hop_penalty5.png" format="PNG" /> </imageobject> <textobject> <phrase>route candidates</phrase> </textobject> </inlinemediaobject> - - +</para> +<para> As B.A.T.M.A.N. IV values TQ and fastest packet the node A's route will point towards the node S. Once the WiFi link quality drops (for a few moments due to some collisions) the TQ value from the node S will drop. At that point the B.A.T.M.A.N. IV node A will change its route towards node B which offers a better TQ value. Node A and node B will send packets forth and back in a loop. </para> <para> To overcome this issue B.A.T.M.A.N. IV introduces a hop penalty: Every time an OGM passes a node the TQ value will be decreased by a fixed value regardless of the asymetric link penalty before rebroadcasting the packet. In the given example it decrease the value of the second route via node B. +</para> +<para> <inlinemediaobject> <imageobject> <imagedata fileref="images/hop_penalty6.pdf" format="EPS" scale="50" /> </imageobject> <imageobject> <imagedata fileref="images/hop_penalty6.png" format="PNG" /> </imageobject> @@ -327,7 +356,19 @@ TODO Explain multiple interfaces, which interface sends which OGM by which TTL, <sect2 id="batman4_tq_echo_cancellation"> <title>Echo cancellation</title> <para> - TODO rebroadcast cancellation by adding IP of previous node because we don't drop packets + As explained in the hop penalty section B.A.T.M.A.N. IV floods the network with more packets than B.A.T.M.A.N. III due to the less strict duplicate detection mechanism. B.A.T.M.A.N. IV checks for unknown sequence numbers via a specific neighbor. If this combination is "new" the OGM will be accepted, processed and rebroadcasted. This may duplicate known information when the message "comes back" due to rebroadcasting (so called echos). In dense areas without heavy packet loss this leads to increased bandwidth and CPU usage. +</para> +<para> + Lets consider the following example: 3 nodes (A, B and C) in a row (A can hear B but not C). Node A emits an OGM, B hears and rebroadcasts it. This broadcast from B arrives at C which also rebroadcasts the message. B will receive the very OGM that it sent before and happily rebroadcast again (the echo of its own message). [figure1] +</para> +<para> + To detect echos (messages that already passed through a node) B.A.T.M.A.N. IV introduces a new protocol field called "old originator" which contains the IP address of the node rebroadcasting the OGM. Whenever a node receives a message from a neighbor it will fill the "old originator" field with the address of this neighbor before rebroadcasting it. If the neighbor recognizes his own IP address in the "old originator" field the packet will be ignored. [figure2] +</para> +<para> + Back to the example: Node B will ignore (drop) the packet coming back from node C as node C wrote the IP address of node B in the "old originator" field. [figure3] +</para> +<para> + Even in more sophisticated scenarios with more nodes/hops this concept successfully reduces the packets. It ensures that packet only travels paths which did not see this OGM before. [figure4] </para> </sect2>

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[doc] batman-adv-doc, master: minor text updates (d881b1e9)
by postmaster＠open-mesh.org 14 Dec '17

14 Dec '17

Repository : ssh://git@open-mesh.org/doc On branches: batman-adv-doc,master >--------------------------------------------------------------- commit d881b1e9be096e019aeacc0c44ad6fa2c3920ecb Author: Marek <marek(a)openmoko.com> Date: Sun Sep 28 15:01:21 2008 +0800 minor text updates >--------------------------------------------------------------- d881b1e9be096e019aeacc0c44ad6fa2c3920ecb batman_iv.docbook | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/batman_iv.docbook b/batman_iv.docbook index 565fe797..9354f25f 100644 --- a/batman_iv.docbook +++ b/batman_iv.docbook @@ -146,7 +146,10 @@ TODO Explain multiple interfaces, which interface sends which OGM by which TTL, The local link quality needs to be propagated throughout the network to inform other nodes about the transmit quality. Therefore B.A.TM.A.N. IV introduces a new field called "TQ" which is 1 byte long. This field is added to the known B.A.T.M.A.N. III packet. Whenever the OGM is generated this field is set to maximum length (256) before it is broadcasted. The receiving neighbor will calculate their own local link quality into the received TQ value and rebroadcast the packet. Hence, every node receiving a packet knows about the transmit quality towards the originator node. </para> <para> - To add the local link quality in the TQ value the following calculation is performed: TQ incoming * local TQ towards this node / TQ max. + To add the local link quality in the TQ value the following calculation is performed: +</para> +<para> + TQ incoming * local TQ towards this node / TQ max. </para> <para> Example: Node A broadcasts the packet with TQ max. Node B receives it, applies the TQ calculation and rebroadcasts it. When node C gets the packet it knows about the transmit quality towards node A. [illustration needed] @@ -163,18 +166,17 @@ TODO Explain multiple interfaces, which interface sends which OGM by which TTL, </orderedlist> </para> <para> - The calculation for the local TQ needs the OGM packet count of the neigbor and the own OGM packet count rebroadcasted by that very neighbor. Therefore a B.A.T.M.A.N. node has keep track of received packets over a certain interval. The slinding window size of these statistics is called TQ_LOCAL_WINDOW_SIZE. [what else shoud be mentioned here ?] + The calculation for the local TQ needs the OGM packet count of the neigbor and the own OGM packet count rebroadcasted by that very neighbor. Therefore a B.A.T.M.A.N. node has keep track of received packets over a certain interval. The slinding window size of these statistics is called TQ_LOCAL_WINDOW_SIZE. </para> <para> - The global TQ is an average of all received TQ values from one originator via a distinct neighbor. Packets with a TQ value of 0 also count as non-received packets. B.A.T.M.A.N. IV uses a sliding window size (TQ_GLOBAL_WINDOW_SIZE) greater than 1 [dat muss noch schöner ...] + The global TQ is an average of all received TQ values from one originator via a distinct neighbor. Packets with a TQ value of 0 also count as non-received packets. B.A.T.M.A.N. IV uses the sliding window size TQ_GLOBAL_WINDOW_SIZE greater than 1 to average the TQ. </para> </sect2> <sect2 id="batman4_tq_asymetry"> <title>Handling asymetric links</title> <para> -TODO Only transmit quality is not enough - nothing worth if the receive - direction is too bad to receive WIFI acks. + Although the transmit link quality is most important B.A.T.M.A.N. IV also keeps track of the receiving link quality. On the WiFi layer every unicast packet has to be acknowledged by the neighbor node. If this neighbor is not able to sucessfully transmit his ACKs the WiFi layer considers this transmission to be failed. <inlinemediaobject> <imageobject> <imagedata fileref="images/asym_link1.pdf" format="EPS" scale="50" /> </imageobject> <imageobject> <imagedata fileref="images/asym_link1.png" format="PNG" /> </imageobject>

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[doc] batman-adv-doc, master: initial text for "Handling asymetric links" (13049888)
by postmaster＠open-mesh.org 14 Dec '17

14 Dec '17

Repository : ssh://git@open-mesh.org/doc On branches: batman-adv-doc,master >--------------------------------------------------------------- commit 1304988897578234d0be07df160836344da11810 Author: Marek <marek(a)openmoko.com> Date: Mon Sep 29 10:21:59 2008 +0800 initial text for "Handling asymetric links" >--------------------------------------------------------------- 1304988897578234d0be07df160836344da11810 batman_iv.docbook | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) diff --git a/batman_iv.docbook b/batman_iv.docbook index 9354f25f..cd50f816 100644 --- a/batman_iv.docbook +++ b/batman_iv.docbook @@ -176,21 +176,29 @@ TODO Explain multiple interfaces, which interface sends which OGM by which TTL, <sect2 id="batman4_tq_asymetry"> <title>Handling asymetric links</title> <para> - Although the transmit link quality is most important B.A.T.M.A.N. IV also keeps track of the receiving link quality. On the WiFi layer every unicast packet has to be acknowledged by the neighbor node. If this neighbor is not able to sucessfully transmit his ACKs the WiFi layer considers this transmission to be failed. + Although the transmit link quality is most important decision factor B.A.T.M.A.N. IV also keeps track of the receiving link quality. On the WiFi layer every unicast packet has to be acknowledged by the neighbor node to approve the transmission. If this neighbor is not able to sucessfully send his ACKs the WiFi layer considers this transmission to be failed and tries to retransmit until it gives up. +</para> +<para> <inlinemediaobject> <imageobject> <imagedata fileref="images/asym_link1.pdf" format="EPS" scale="50" /> </imageobject> <imageobject> <imagedata fileref="images/asym_link1.png" format="PNG" /> </imageobject> <textobject> <phrase>Asymetry situation without asymetry penalty</phrase> </textobject> </inlinemediaobject> - - -TODO Also calculate the receive direction - but weight it. +</para> +<para> + Thus B.A.T.M.A.N. IV needs to penalize links that have have a poor receiving link quality. To avoid a simple hysteresis which completely turns on or off a link B.A.T.M.A.N. IV uses a mathematical function to give the receiving link quality stronger negative impact the weaker the link becomes. +</para> +<para> <inlinemediaobject> <imageobject> <imagedata fileref="images/asym_penalty.pdf" format="EPS" /> </imageobject> <imageobject> <imagedata fileref="images/asym_penalty.png" format="PNG" /> </imageobject> <textobject> <phrase>graph for asymetry penalty</phrase> </textobject> </inlinemediaobject> - +</para> +<para> + This obtained value is calculated into the TQ before it gets rebroadcasted. Neighboring nodes can weight the routing decision based on this information. In some situations the weak link is the only link available, so you want to use it, whereas in other cases better connections may exist. +</para> +<para> <inlinemediaobject> <imageobject> <imagedata fileref="images/asym_link2.pdf" format="EPS" scale="50" /> </imageobject> <imageobject> <imagedata fileref="images/asym_link2.png" format="PNG" /> </imageobject>

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[doc] batman-adv-doc, master: add diagram for tq propagation (377db766)
by postmaster＠open-mesh.org 14 Dec '17

14 Dec '17

Repository : ssh://git@open-mesh.org/doc On branches: batman-adv-doc,master >--------------------------------------------------------------- commit 377db7667ec6d390757103266302c589f6724864 Author: Simon Wunderlich <siwu(a)hrz.tu-chemnitz.de> Date: Thu Oct 9 18:31:19 2008 +0200 add diagram for tq propagation >--------------------------------------------------------------- 377db7667ec6d390757103266302c589f6724864 batman_iv.docbook | 11 ++++++++++- images/Makefile | 2 +- images/tq_prop.dia | Bin 0 -> 2024 bytes 3 files changed, 11 insertions(+), 2 deletions(-) diff --git a/batman_iv.docbook b/batman_iv.docbook index cd50f816..8b6dddd8 100644 --- a/batman_iv.docbook +++ b/batman_iv.docbook @@ -152,7 +152,16 @@ TODO Explain multiple interfaces, which interface sends which OGM by which TTL, TQ incoming * local TQ towards this node / TQ max. </para> <para> - Example: Node A broadcasts the packet with TQ max. Node B receives it, applies the TQ calculation and rebroadcasts it. When node C gets the packet it knows about the transmit quality towards node A. [illustration needed] + Example: Node A broadcasts the packet with TQ max. Node B receives it, applies the TQ calculation and rebroadcasts it. When node C gets the packet it knows about the transmit quality towards node A. +</para> +<para> + <inlinemediaobject> + <imageobject> <imagedata fileref="images/tq_prop.pdf" format="EPS" scale="40" /> </imageobject> + <imageobject> <imagedata fileref="images/tq_prop.png" format="PNG" /> </imageobject> + <textobject> <phrase>Transmit Link Quality (TQ)</phrase> </textobject> + </inlinemediaobject> + + </para> </sect2> diff --git a/images/Makefile b/images/Makefile index ae167d56..acca3164 100644 --- a/images/Makefile +++ b/images/Makefile @@ -1,5 +1,5 @@ GP_IMAGES=asym_penalty.gp -DIA_IMAGES=asymetry.dia tq.dia eq.dia rq.dia hop_penalty1.dia hop_penalty2.dia asym_link1.dia asym_link2.dia +DIA_IMAGES=asymetry.dia tq.dia eq.dia rq.dia hop_penalty1.dia hop_penalty2.dia asym_link1.dia asym_link2.dia tq_prop.dia PNG_IMAGES= $(DIA_IMAGES:.dia=.png) PNG_IMAGES+=$(GP_IMAGES:.gp=.png) PDF_IMAGES= $(DIA_IMAGES:.dia=.pdf) diff --git a/images/tq_prop.dia b/images/tq_prop.dia new file mode 100644 index 00000000..5af3eb1a Binary files /dev/null and b/images/tq_prop.dia differ

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[doc] batman-adv-doc, master: add formulas (plus Makefile voodoo to generate them from tex) (2763c2af)
by postmaster＠open-mesh.org 14 Dec '17

14 Dec '17

Repository : ssh://git@open-mesh.org/doc On branches: batman-adv-doc,master >--------------------------------------------------------------- commit 2763c2af03d69782b207428af749f99ffe9c97fa Author: Simon Wunderlich <siwu(a)hrz.tu-chemnitz.de> Date: Thu Oct 9 19:57:51 2008 +0200 add formulas (plus Makefile voodoo to generate them from tex) >--------------------------------------------------------------- 2763c2af03d69782b207428af749f99ffe9c97fa batman_iv.docbook | 24 +++++++++++++++++------- images/Makefile | 19 +++++++++++++++++++ images/compute_tq.tex | 6 ++++++ images/tq_prop_calc.tex | 6 ++++++ 4 files changed, 48 insertions(+), 7 deletions(-) diff --git a/batman_iv.docbook b/batman_iv.docbook index 8b6dddd8..26c02a8a 100644 --- a/batman_iv.docbook +++ b/batman_iv.docbook @@ -131,13 +131,19 @@ TODO Explain multiple interfaces, which interface sends which OGM by which TTL, <imageobject> <imagedata fileref="images/tq.pdf" format="EPS" scale="50" /> </imageobject> <imageobject> <imagedata fileref="images/tq.png" format="PNG" /> </imageobject> <textobject> <phrase>Transmit Link Quality (TQ)</phrase> </textobject> - </inlinemediaobject></para> + </inlinemediaobject></para> + <para> + <inlinemediaobject> + <imageobject> <imagedata fileref="images/compute_tq.pdf" format="EPS"/> </imageobject> + <imageobject> <imagedata fileref="images/compute_tq.png" format="PNG" /> </imageobject> + <textobject> <phrase>compute the Transmit Link Quality</phrase> </textobject> + </inlinemediaobject> + </para> + </listitem> </orderedlist> - - As shown above B.A.T.M.A.N. IV is able to retrieve the local transmit quality by using the same mechanisms as B.A.T.M.A.N. III without adding further overhead. -[4 illustrations needed (for each list item and one for the tq alone)] -[??? what kind of 4th illustration? put the formular in a picture, or in the text?] + This shows that B.A.T.M.A.N. IV is able to compute the local Transmit Quality by using the same + mechanisms as B.A.T.M.A.N. III without adding further overhead. </para> </sect2> <sect2 id="batman4_tq_prop"> @@ -149,7 +155,11 @@ TODO Explain multiple interfaces, which interface sends which OGM by which TTL, To add the local link quality in the TQ value the following calculation is performed: </para> <para> - TQ incoming * local TQ towards this node / TQ max. + <inlinemediaobject> + <imageobject> <imagedata fileref="images/tq_prop_calc.pdf" format="EPS" /> </imageobject> + <imageobject> <imagedata fileref="images/tq_prop_calc.png" format="PNG" /> </imageobject> + <textobject> <phrase>TQ calcuation</phrase> </textobject> + </inlinemediaobject> </para> <para> Example: Node A broadcasts the packet with TQ max. Node B receives it, applies the TQ calculation and rebroadcasts it. When node C gets the packet it knows about the transmit quality towards node A. @@ -158,7 +168,7 @@ TODO Explain multiple interfaces, which interface sends which OGM by which TTL, <inlinemediaobject> <imageobject> <imagedata fileref="images/tq_prop.pdf" format="EPS" scale="40" /> </imageobject> <imageobject> <imagedata fileref="images/tq_prop.png" format="PNG" /> </imageobject> - <textobject> <phrase>Transmit Link Quality (TQ)</phrase> </textobject> + <textobject> <phrase>TQ propagation</phrase> </textobject> </inlinemediaobject> diff --git a/images/Makefile b/images/Makefile index acca3164..fd71db05 100644 --- a/images/Makefile +++ b/images/Makefile @@ -1,9 +1,12 @@ GP_IMAGES=asym_penalty.gp DIA_IMAGES=asymetry.dia tq.dia eq.dia rq.dia hop_penalty1.dia hop_penalty2.dia asym_link1.dia asym_link2.dia tq_prop.dia +TEX_IMAGES=compute_tq.tex tq_prop_calc.tex PNG_IMAGES= $(DIA_IMAGES:.dia=.png) PNG_IMAGES+=$(GP_IMAGES:.gp=.png) +PNG_IMAGES+=$(TEX_IMAGES:.tex=.png) PDF_IMAGES= $(DIA_IMAGES:.dia=.pdf) PDF_IMAGES+=$(GP_IMAGES:.gp=.pdf) +PDF_IMAGES+=$(TEX_IMAGES:.tex=.pdf) .PHONY: clean .SUFFIXES: .dia .png .eps .pdf .gp @@ -22,6 +25,22 @@ all: $(PDF_IMAGES) $(PNG_IMAGES) /usr/bin/dia -e $@ $< .eps.pdf: /usr/bin/epstopdf --outfile=$@ $< +.tex.pdf: + rm -f file_tmp.* + cp $< file_tmp.tex + latex file_tmp.tex + dvips file_tmp.dvi + ps2eps -l file_tmp.ps + epstopdf file_tmp.eps + mv file_tmp.pdf $@ + rm -f file_tmp.* +.tex.png: + rm -f file_tmp.* + cp $< file_tmp.tex + latex file_tmp.tex + dvips -x 3000 -y 3000 -E file_tmp.dvi + convert file_tmp.ps $@ + rm -f file_tmp.* clean: rm -f *.png *.eps *.pdf diff --git a/images/compute_tq.tex b/images/compute_tq.tex new file mode 100644 index 00000000..71f7bd75 --- /dev/null +++ b/images/compute_tq.tex @@ -0,0 +1,6 @@ +\documentclass{article} +\pagestyle{empty} +\begin{document} +$EQ = RQ \cdot TQ \qquad \Rightarrow \qquad TQ = \frac{EQ}{RQ}$ +\end{document} + diff --git a/images/tq_prop_calc.tex b/images/tq_prop_calc.tex new file mode 100644 index 00000000..23b71086 --- /dev/null +++ b/images/tq_prop_calc.tex @@ -0,0 +1,6 @@ +\documentclass{article} +\pagestyle{empty} +\begin{document} +$TQ = TQ_{incoming} * TQ_{local}$ +\end{document} +

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[doc] batman-adv-doc, master: add some alternative illustration for the echo quality (33ded001)
by postmaster＠open-mesh.org 14 Dec '17

14 Dec '17

Repository : ssh://git@open-mesh.org/doc On branches: batman-adv-doc,master >--------------------------------------------------------------- commit 33ded0015dfe712af138e6a3091c393eca68be69 Author: Simon Wunderlich <siwu(a)hrz.tu-chemnitz.de> Date: Thu Oct 9 20:02:35 2008 +0200 add some alternative illustration for the echo quality (only generated, not in the docbook) >--------------------------------------------------------------- 33ded0015dfe712af138e6a3091c393eca68be69 images/Makefile | 3 ++- images/eq_alt1.dia | Bin 0 -> 1138 bytes images/eq_alt2.dia | Bin 0 -> 1139 bytes images/eq_alt3.dia | Bin 0 -> 1136 bytes 4 files changed, 2 insertions(+), 1 deletion(-) diff --git a/images/Makefile b/images/Makefile index fd71db05..b36bed35 100644 --- a/images/Makefile +++ b/images/Makefile @@ -1,5 +1,6 @@ GP_IMAGES=asym_penalty.gp -DIA_IMAGES=asymetry.dia tq.dia eq.dia rq.dia hop_penalty1.dia hop_penalty2.dia asym_link1.dia asym_link2.dia tq_prop.dia +DIA_IMAGES=asymetry.dia tq.dia eq.dia eq_alt1.dia eq_alt2.dia eq_alt3.dia rq.dia \ + hop_penalty1.dia hop_penalty2.dia asym_link1.dia asym_link2.dia tq_prop.dia TEX_IMAGES=compute_tq.tex tq_prop_calc.tex PNG_IMAGES= $(DIA_IMAGES:.dia=.png) PNG_IMAGES+=$(GP_IMAGES:.gp=.png) diff --git a/images/eq_alt1.dia b/images/eq_alt1.dia new file mode 100644 index 00000000..ec32db21 Binary files /dev/null and b/images/eq_alt1.dia differ diff --git a/images/eq_alt2.dia b/images/eq_alt2.dia new file mode 100644 index 00000000..ab85fd17 Binary files /dev/null and b/images/eq_alt2.dia differ diff --git a/images/eq_alt3.dia b/images/eq_alt3.dia new file mode 100644 index 00000000..8623e9bc Binary files /dev/null and b/images/eq_alt3.dia differ

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[doc] batman-adv-doc, master: use alternative 1 for echo quality (eebed9b0)
by postmaster＠open-mesh.org 14 Dec '17

14 Dec '17

Repository : ssh://git@open-mesh.org/doc On branches: batman-adv-doc,master >--------------------------------------------------------------- commit eebed9b0178504f0304818aad14fd6679d0ad6e0 Author: Simon Wunderlich <siwu(a)hrz.tu-chemnitz.de> Date: Fri Oct 10 12:18:57 2008 +0200 use alternative 1 for echo quality >--------------------------------------------------------------- eebed9b0178504f0304818aad14fd6679d0ad6e0 batman_iv.docbook | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/batman_iv.docbook b/batman_iv.docbook index 26c02a8a..dbcb4a4c 100644 --- a/batman_iv.docbook +++ b/batman_iv.docbook @@ -119,8 +119,8 @@ TODO Explain multiple interfaces, which interface sends which OGM by which TTL, <para>B.A.T.M.A.N. knows the echo link quality (EQ) by counting rebroadcasts of its own OGMs from his neighbors.</para> <para> <inlinemediaobject> - <imageobject> <imagedata fileref="images/eq.pdf" format="EPS" scale="50" /> </imageobject> - <imageobject> <imagedata fileref="images/eq.png" format="PNG" /> </imageobject> + <imageobject> <imagedata fileref="images/eq_alt1.pdf" format="EPS" scale="50" /> </imageobject> + <imageobject> <imagedata fileref="images/eq_alt1.png" format="PNG" /> </imageobject> <textobject> <phrase>Echo Link Quality (EQ)</phrase> </textobject> </inlinemediaobject></para> </listitem>

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