Convergence times
Issue 3.4.1 June 2005
355
Convergence times
Convergence is the time that it takes from the instant a failure occurs in the network until a new
path through the network is discovered, and all routers or switches are aware of the new path.
Convergence times vary, based on the complexity and size of a network.
Table 82: Sample
convergence times (single link failure)
lists some sample convergence times that are based on
a single link failing in a relatively simple network. They reflect update and/or hello timers
expiring. Dialup “convergence” times reflect the time that it takes to dial, connect, and
authenticate a connection. These times do not take into account LAG, fast spanning tree, or
multipath routing, which speed up convergence. This table shows the importance of carefully
planning for fail-over in a network. For example, both OSPF and EIGRP (Layer 3) protocols
converge faster than spanning tree (Layer 2). When designing a highly available data network, it
is more advantageous to use Layer 3 protocols, especially link-state (OSPF) or hybrid (EIGRP)
protocols, than Layer 2 (spanning tree).
Table 82: Sample convergence times (single link failure)
Protocol
Approximate convergence
time (seconds)
EIGRP (Cisco)
2
OSPF
6 to 46
RIP
210
IGRP (Cisco)
400
Spanning tree (Layer 2)
50+
ISDN dialup (c
authentication)
2
56-k dialup (c
authentication)
60
Summary of Contents for Application Solutions
Page 1: ...Avaya Application Solutions IP Telephony Deployment Guide 555 245 600 Issue 3 4 1 June 2005 ...
Page 20: ...About This Book 20 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 21: ...Issue 3 4 1 June 2005 21 Section 1 Avaya Application Solutions product guide ...
Page 22: ...22 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 106: ...Call processing 106 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 124: ...Avaya LAN switching products 124 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 139: ...Issue 3 4 1 June 2005 139 Section 2 Deploying IP Telephony ...
Page 140: ...140 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 186: ...Traffic engineering 186 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 204: ...Security 204 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 228: ...Avaya Integrated Management 228 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 274: ...Reliability and Recovery 274 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 275: ...Issue 3 4 1 June 2005 275 Section 3 Getting the IP network ready for telephony ...
Page 276: ...276 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 356: ...Network recovery 356 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 366: ...Network assessment offer 366 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 367: ...Issue 3 4 1 June 2005 367 Appendixes ...
Page 368: ...Appendixes 368 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 394: ...Access list 394 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 414: ...DHCP TFTP 414 Avaya Application Solutions IP Telephony Deployment Guide ...