Packet Switching - Cisco 1601R User Manual

C1600 processor with 6144 Kbytes of main memory
program load complete, entry point: 0x4018060, size: 0x1da950
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Cisco Internetwork Operating System Software
IOS (tm) 1600 Software (C1600−Y−L), Version 12.2(10b),
RELEASE SOFTWARE (fc1)
Copyright (c) 1986−2001 by cisco Systems, Inc.
Compiled Fri 12−Jul−02 03:29 by pwade
Image text−base: 0x0803A50C, data−base: 0x02005000cisco 1604
(68360) processor (revision C) with 4608K/1536K bytes of memory.
Processor board ID 04607098, with hardware revision 00000000
Bridging software.
X.25 software, Version 3.0.0.
Basic Rate ISDN software, Version 1.1.
1 Ethernet/IEEE 802.3 interface(s)
1 ISDN Basic Rate interface(s)
U interface with external S bus interface for ISDN Basic Rate interface.
System/IO memory with parity disabled
2048K bytes of DRAM onboard 4096K bytes of DRAM on SIMM
System running from FLASH
7K bytes of non−volatile configuration memory.
16384K bytes of processor board PCMCIA flash (Read ONLY)
Press RETURN to get started!
00:00:36: %SYS−5−CONFIG_I: Configured from memory by console
00:00:36: %SYS−5−RESTART: System restarted −−
Cisco Internetwork Operating System Software
IOS (tm) 1600 Software (C1600−Y−L), Version 12.2(10b),
RELEASE SOFTWARE (fc1)
Copyright (c) 1986−2002 by cisco Systems, Inc.
Compiled Fri 12−Jul−02 03:29 by pwade
Router−1600>

Packet Switching

The switching architecture of the Cisco 1600 Series Router is based on the shared memory architecture. The
Cisco 2500, 4x00 and AS5300 Series also use this switching architecture.
Cisco IOS software on shared memory routers uses the system buffers for all packet switching, not just
process switching. In addition to the standard public buffer pools, the Cisco IOS software also creates private
system buffer pools and special buffer structures for the interface controllers called RX rings and TX rings.
Private Buffer Pools
Private buffer pools are static, and are allocated with a fixed number of buffers during initialization of the
Cisco IOS software. New buffers cannot be created on demand for these pools. If a buffer is needed, and none
Cisco − Cisco 1600 Series Router Architecture
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