Lectures notes for 2010 - KTH
Lectures notes for 2010 - KTH Lectures notes for 2010 - KTH
Sliding window Flow control • receiver: offered window - acknowledges data sent and what it is prepared to receive • thus the sender can send an ACK, but with a offered window of 0 • later the sender sends a window update with a non-zero offered window size • the receiver can increase or decrease this window size as it wants • sender: usable window - how much data it is prepared to send immediately receiver’s offered window Usable Window segment number 1 2 3 4 5 6 6 7 8 9 10 11 12 13 14 sent and acknowledged sent but unacknowledged can’t send until can send window advances this much more Maguire TCP header continued 5: 14 of 77 maguire@kth.se 2010.03.21 Internetworking/Internetteknik
Window size Increasing window size can improve performance - more recent systems have increased buffer size ranging from 4096 ... 16,384 bytes. The later produces ~40% increase in file transfer performance on an ethernet. Socket API allows user to change the size of the send and receive buffers. Maguire TCP header continued 5: 15 of 77 maguire@kth.se 2010.03.21 Internetworking/Internetteknik
- Page 269 and 270: DHCP’s importance • allows reus
- Page 271 and 272: Example of dhcpd.conf ### Managed b
- Page 273 and 274: Trivial File Transfer Procotol (TFT
- Page 275 and 276: Mapping names to IP addresses Host
- Page 277 and 278: Zones A zone is a subtree of the DN
- Page 279 and 280: (see Stevens, Vol. 1, figure 14.2,
- Page 281 and 282: Domain registrars Internet Corporat
- Page 283 and 284: Resource Records (RR) See Stevens,
- Page 285 and 286: Network names Conventions: • it.k
- Page 287 and 288: Example: $ORIGIN it.kth.se. @ 1D IN
- Page 289 and 290: How to give your host a name? Host
- Page 291 and 292: Configuring DNS • Configuring the
- Page 293 and 294: Load leveling [1] For example, f.ro
- Page 295 and 296: Where is f.root-servers.net ? trace
- Page 297 and 298: Dynamic Domain Name System (DDNS) R
- Page 299 and 300: Attacks upon DNS • Denial of serv
- Page 301 and 302: DNS performance - top 100 From www.
- Page 303 and 304: Web performance - continued Using P
- Page 305 and 306: This lecture we have discussed: •
- Page 307 and 308: IK1550 Internetworking/Internettekn
- Page 309 and 310: Transport layer protocols • User
- Page 311 and 312: Applications which use TCP Lots of
- Page 313 and 314: TCP header continued Reliability is
- Page 315 and 316: time client SYN, seq=x SYN, seq=y,
- Page 317 and 318: client active close ACKs from clien
- Page 319: Maximum Segment Size • The Maximu
- Page 323 and 324: Silly Window Syndrome If receiver a
- Page 325 and 326: Disabling the Nagle Algorithm But s
- Page 327 and 328: Resulting bulk data flow Every segm
- Page 329 and 330: Congestion Avoidance So far we have
- Page 331 and 332: Slow start In 1989, Van Jacobson in
- Page 333 and 334: Round-Trip Time Measurement Fundame
- Page 335 and 336: Congestion Avoidance Algorithm Slow
- Page 337 and 338: Per-Route Metrics Newer TCPs keeps
- Page 339 and 340: TCP Keepalive Timer No data flows a
- Page 341 and 342: Long Fat Pipes Networks with large
- Page 343 and 344: Example of TCP behavior 1 1. Figure
- Page 345 and 346: Hypertext Transfer Protocol (HTTP)
- Page 347 and 348: HTTP Requests request-line == reque
- Page 349 and 350: HTTP Response Codes HTTP 3-digit re
- Page 351 and 352: Server Redirect Response code 302,
- Page 353 and 354: Decrease in total time to produce a
- Page 355 and 356: HTTP Statistics Statistics for indi
- Page 357 and 358: HTTP Performance Problems HTTP open
- Page 359 and 360: Web Enabled Devices emWare - thin c
- Page 361 and 362: Remote Procedure Call (RPC) Two ver
- Page 363 and 364: External Data Representation (XDR)
- Page 365 and 366: NFSspy Insert a new pointer in plac
- Page 367 and 368: nfsspy Initial implementations were
- Page 369 and 370: Often there are multiple NFS client
Sliding window Flow control<br />
• receiver: offered window - acknowledges data sent and what it is<br />
prepared to receive<br />
• thus the sender can send an ACK, but with a offered window of 0<br />
• later the sender sends a window update with a non-zero offered window size<br />
• the receiver can increase or decrease this window size as it wants<br />
• sender: usable window - how much data it is prepared to send<br />
immediately<br />
receiver’s<br />
offered window<br />
Usable Window<br />
segment<br />
number<br />
1 2 3 4 5 6 6 7 8 9 10 11 12 13 14<br />
sent and<br />
acknowledged<br />
sent but<br />
unacknowledged<br />
can’t send until<br />
can send window advances<br />
this much more<br />
Maguire TCP header continued 5: 14 of 77<br />
maguire@kth.se <strong>2010</strong>.03.21 Internetworking/Internetteknik
Change language