Exit Zen
116
../../protocols/ipv6.rst:402
English
Datalink layer
0/140 · 14
116
../../protocols/ethernet.rst:375 • ../../protocols/ethernet.rst:375 • ../../protocols/ethernet.rst:376
English
no
0/100 · 2
116
../../protocols/tcp.rst:336
English
5.24 Mbps
0/100 · 9
117
../../glossary.rst:125
English
A TCP option used by a TCP entity in SYN segments to indicate the Maximum Segment Size that it is able to receive.
0/1140 · 114
117
../../principles/network.rst:513
English
One of the objectives of the `control plane` in the network layer is to maintain the routing tables that are used on all routers. As indicated earlier, a routing table is a data structure that contains, for each destination address (or block of addresses) known by the router, the outgoing interface over which the router must forward a packet destined to this address. The routing table may also contain additional information such as the address of the next router on the path towards the destination or an estimation of the cost of this path.
0/5450 · 545
117
../../principles/reliability.rst:410
English
`1101` is encoded as `11011`
0/280 · 28
117
../../principles/transport.rst:659
English
Transport clock
0/150 · 15
117
../../principles/sharing.rst:546
English
Collisions with CSMA/CA
0/230 · 23
117
../../protocols/bgp.rst:425
English
`AS4` sends `U(p,AS4:AS0)` to `AS1` and `AS3`. `AS3` prefers the path via `AS4`.
0/800 · 80
117
../../protocols/email.rst:250
English
26
0/100 · 2
117
../../protocols/ethernet.rst:423
English
The [IEEE802.1q]_ header is inserted immediately after the source MAC address in the Ethernet frame (i.e. before the EtherType field). The maximum frame size is increased by 4 bytes. It is encoded in 32 bits and contains four fields. The Tag Protocol Identifier is set to `0x8100` to allow the receiver to detect the presence of this additional header. The `Priority Code Point` (PCP) is a three bit field that is used to support different transmission priorities for the frame. Value `0` is the lowest priority and value `7` the highest. Frames with a higher priority can expect to be forwarded earlier than frames having a lower priority. The `C` bit is used for compatibility between Ethernet and Token Ring networks. The last 12 bits of the 802.1q header contain the VLAN identifier. Value `0` indicates that the frame does not belong to any VLAN while value `0xFFF` is reserved. This implies that 4094 different VLAN identifiers can be used in an Ethernet network.
0/9690 · 969
117
../../protocols/ipv6.rst:402
English
MTU
0/100 · 3
117
../../protocols/ethernet.rst:376
English
Root
0/100 · 4
117
../../protocols/tcp.rst:337 • ../../protocols/tcp.rst:350
English
500 msec
0/100 · 8
118
../../glossary.rst:21
English
multicast
0/100 · 9
118
../../principles/network.rst:515
English
In this section, we discuss the main techniques that can be used to maintain the forwarding tables in a network.
0/1120 · 112
118
../../principles/reliability.rst:412
English
This parity scheme has been used in some RAMs as well as to encode characters sent over a serial line. It is easy to show that this coding scheme allows the receiver to detect a single transmission error, but it cannot correct it. However, if two or more bits are in error, the receiver may not always be able to detect the error.
0/3300 · 330
118
../../principles/transport.rst:662
English
It should be noted that `transport clocks` do not need and usually are not synchronized to the real-time clock. Precisely synchronizing real-time clocks is an interesting problem, but it is outside the scope of this document. See [Mills2006]_ for a detailed discussion on synchronizing the real-time clock.
0/3060 · 306
118
../../principles/sharing.rst:552
English
To deal with this problem, CSMA/CA relies on a backoff timer. This backoff timer is a random delay that is chosen by each device in a range that depends on the number of retransmissions for the current frame. The range grows exponentially with the retransmissions as in CSMA/CD. The minimum range for the backoff timer is :math:`[0,7*slotTime]` where the `slotTime` is a parameter that depends on the underlying physical layer. Compared to CSMA/CD's exponential backoff, there are two important differences to notice. First, the initial range for the backoff timer is seven times larger. This is because it is impossible in CSMA/CA to detect collisions as they happen. With CSMA/CA, a collision may affect the entire frame while with CSMA/CD it can only affect the beginning of the frame. Second, a CSMA/CA device must regularly sense the transmission channel during its back off timer. If the channel becomes busy (i.e. because another device is transmitting), then the back off timer must be frozen until the channel becomes free again. Once the channel becomes free, the back off timer is restarted. This is in contrast with CSMA/CD where the back off is recomputed after each collision. This is illustrated in the figure below. Host `A` chooses a smaller backoff than host `C`. When `C` senses the channel to be busy, it freezes its backoff timer and only restarts it once the channel is free again.
0/14030 · 1403
118
../../protocols/bgp.rst:426
English
`AS3` sends `U(p,AS3:AS4:AS0)` to `AS1` and `W(p)` to `AS4`. `AS1` switches back to the direct path and we are back at the first step.
0/1340 · 134