The name has three parts, separated by dashes: e.g. xxxx-yyyy-ww:

xxxx = Platform

yyyy = Features

ww = Format - Where it executes from if compressed.

　
Software Naming Conventions for IOS - Platform
as5200
5200

ca1003
Cisco Advantage 1003

ca1005
Cisco Advantage 1005

cpa1003
CiscoPro 1003,4

cpa1005
CiscoPro 1005

cpa25
CiscoPro 2500

cpa3620
CiscoPro 3620

cpa3640
CiscoPro 3640

cpa45
CiscoPro 4500

*cs
Communication Server

cs500
cs500

c1000
1003,4

c1005
1005

c1600
1600

c2500
25xx,3xxx,5100, AO (11.2 and later only)

c25fx
Fixed Frad

c2600
2600 Quake

c2800
Catalyst 2800

c2900
2910, 2950

c29atm
2900 ATM

c3620
3620

c3640
3640

c3800
3800

c4000
4000 (11.2 and later only)

c4500
4500, 4700

c5rsfc
　
c5rsm
Catalyst 5k RSP

c5atm
Catalyst ATM

c6400s
6400 NSP

c6400r
6400 NRP

c6msm
Catalyst

c7000
7000,7010 (11.2 and later only)

c7200
7200

igs
IGS, 25xx,3xxx,5100, AP

gs3
gateway server (AGS, AGS+)

gs7
gateway server(7000,7010)

gsr
Gigabit Switch Router (12000)

ls1010
Lightstream 1010

mc3810
Ardent Multiservice Cisco 3810

p
Partners platform n

*pt
prootocol translator

rpm
MGX 8850

rsp
75xx

ubr7200
Universal Broadband Router 7200

ubr900
Universal Broadband Router 900

ubr920
Universal Broadband Router 920

vcw
Voice Card Ware

xx
4000

igsetx
2500 (media specific image that supports only ethernet, token ring, and x.25)

　
Software Naming Conventions for IOS - Format

Where the image runs in the router

f flash
m ram
r rom
l relocatable

Compression Types

z zip compressed (note lower case)
x mzip compressed
w "STAC" compressed

Extensions

.tar A utility and file format used for packaging files together. These files are compressed using gzip or some other form of compression
.html The file is used with a Web browser application.

Software Naming Conventions for IOS - Features
　

ALL 0-9 a b c d e f g h i j k l m n o p q r s t u v w x y z ALL

a
a APPN
a2 ATM
a3 APPN replacement

b
b Appletalk
boot boot image

c
c Comm-server/Remote Access Server (RAS) subset (SNMP, IP, Bridging,IPX, Atalk, Decnet, FR, HDLC, PPP, X,25, ARAP, tn3270, PT,
XRemote, LAT) (non-CiscoPro)
c CommServer lite (CiscoPro)
c2 Comm-server/Remote Access Server (RAS) subset (SNMP, IP, Bridging,IPX, Atalk, Decnet, FR, HDLC, PPP, X,25, ARAP, tn3270, PT,
XRemote, LAT) (CiscoPro)
c3 clustering

d
d Desktop subset (SNMP, IP, Bridging, WAN, Remote Node, Terminal
Services, IPX, Atalk, ARAP)
(11.2 - Decnet)
d2 reduced Desktop subset(SNMP, IP, IPX, ATALK, ARAP)
diag IOS based diagnostic images

e
e IPeXchange (no longer used in 11.3 and later)
- StarPipes DB2 Access - Enables Cisco IOS to act as a "Gateway" to
all IBM DB2 products for downstream clients/servers in 11.3T
eboot ethernet boot image for mc3810 platform

f
f FRAD subset (SNMP, FR, PPP, SDLLC, STUN)
f2 modified FRAD subset, EIGRP, Pcbus, Lan Mgr removed, OSPF added

g
g ISDN subset (SNMP, IP, Bridging, ISDN, PPP, IPX, Atalk)
g2 gatekeeper proxy, voice and video
g3 ISDN subset for c800 (IP, ISDN, FR)

h
h For Malibu(2910), 8021D, switch functions, IP Host
hdiag Diagnostics image for Malibu(2910)

i (used for image names of platforms c2500 and larger)
i IP subset (SNMP, IP, Bridging, WAN, Remote Node, Terminal Services)
i2 subset similar to IP subset for system controller image (3600)
i3 reduced IP subset with BGP/MIB, EGP/MIB, NHRP, DIRRESP removed.
i4 subset of IP (5200)
ipss7 IP subset with SS7 (2600)

j
j enterprise subset (formerly bpx, includes protocol translation)
*** not used until 10.3 ***

k
k kitchen sink (enterprise for high-end) (same as bx) (Not used after 10.3)
k1 Baseline Privacy key encryption (On 11.3 and up)
k2 high-end enterprise w/CIP2 ucode (Not used after 10.3)
k2 Triple DES (On 11.3 and up)
k3 56bit SSH encryption
k4 168bit SSH encryption
k5 Reserved for future encryption capabilities (On 11.3 and up)
k6 Reserved for future encryption capabilities (On 11.3 and up)
k7 Reserved for future encryption capabilities (On 11.3 and up)
k8 Reserved for future encryption capabilities (On 11.3 and up)
k9 Reserved for future encryption capabilities (On 11.3 and up)
　 　

l
l IPeXchange IPX, static routing, gateway

m
m RMON (11.1 only)
m Catalyst 2820-kernel, parser, ATM signaling, Lane Client, bridging

n
n IPX

o
o Firewall (formerly IPeXchange Net Management)
o2 Firewall (3xx0)
o3 Firewall with ssh (36x0 26x0)

p
p Service Provider (IP RIP/IGRP/EIGRP/OSPF/BGP, CLNS ISIS/IGRP)
p2 Service Provider w/CIP2 ucode
p3 as5200 service provider
p4 5800 (Nitro) service provider
p5 Service Provider (6400 NRP)
p7 Service Provider with PT/TARP (2600, 3640)

q
q Async
q2 IPeXchange Async

r
r IBM base option (SRB, SDLLC, STUN, DLSW, QLLC) - used with
i, in, d (See note below.)
r2 IBM variant for 1600 images
r3 IBM variant for Ardent images (3810)
r4 reduced IBM subset with BSC/MIB, BSTUN/MIB, ASPP/MIB, RSRB/MIB removed.

s
s source route switch (SNMP, IP, Bridging, SRB) (10.2 to 11.1)
s Additions by Platform via PLUS packs

c1000 (OSPF, PIM, SMRP, NLSP, ATIP, ATAURP, FRSVC, RSVP, NAT)
c1005 (X.25, full WAN, OSPF, PIM, NLSP, SMRP, ATIP, ATAURP, FRSVC, RSVP, NAT)
c1600 (OSPF, IPMULTICAST, NHRP, NTP, NAT, RSVP, FRAME_RELAY_SVC)
AT "s" images also have: (SMRP,ATIP,AURP)
IPX "s" images also have: (NLSP,NHRP)
c2500 (NAT, RMON, IBM, MMP, VPDN/L2F)
c2600 (NAT, IBM, MMP, VPDN/L2F, VOIP and ATM)
c3620 (NAT, IBM, MMP, VPDN/L2F) In 11.3T added VOIP
c3640 (NAT, IBM, MMP, VPDN/L2F) In 11.3T added VOIP
c4000 (NAT, IBM, MMP, VPDN/L2F)
c4500 (NAT, ISL, LANE, IBM, MMP, VPDN/L2F)
c5200 (PT, v.120, managed modems, RMON, MMP, VPDN/L2F)
c5300 (MMP, VPDN, NAT, Modem Management, RMON, IBM)
c5rsm (NAT, LANE and VLANS)
c7000 (ISL, LANE, IBM, MMP, VPDN/L2F)
c7200 (NAT, ISL, IBM, MMP, VPDN/L2F)
rsp (NAT, ISL, LANE, IBM, MMP, VPDN/L2F)

　

t
t AIP w/ modified Ucode to connect to Teralink 1000 Data (11.2)
t Telco return (12.0)

u
u IP with VLAN RIP (Network Layer 3 Switching Software, rsrb, srt, srb, sr/tlb)
　 　

v
v VIP and dual RSP (HSA) support
v2 Voice V2D
v3 Voice Feature Card
v4 Voice (ubr920)

w
w WBU Feature Sets

i IISP
l LANE & PVC
p PNNI
v PVC trafffic shaping

　

w2 Cisco Advantage ED train Feature Sets

a IPX, static routing, gateway
b Net Management
c FR/X25
y Async

　

w3 Distributed Director Feature Sets

x
x X.25 in 11.1 and earlier releases and on c800 in 12.0T
x FR/X.25 in 11.2 (IPeXchange)
x H.323 Gatekeeper/Proxy in 11.3 and later releases for 2500, 3620, 3640, mc3810

y (used for image names of platforms smaller than c2500)
y reduced IP (SNMP, IP RIP/IGRP/EIGRP, Bridging, ISDN, PPP) (C1003/4)
y reduced IP (SNMP, IP RIP/IGRP/EIGRP, Bridging, WAN - X.25) (C1005)
(11.2 - includes X.25) (c1005)
y IP variant (no Kerberos, Radius, NTP, OSPF, PIM, SMRP, NHRP...) (c1600)
y2 IP variant (SNMP, IP RIP/IGRP/EIGRP, WAN - X.25, OSPF, PIM) (C1005)
y2 IP Plus variant (no Kerberos, Radius, NTP, ...) (c1600)
y3 IP/X.31
y4 reduced IP variant (Cable, Mibs, DHCP, EZHTTP)
y5 reduced IP variant (Cable, Mibs, DHCP, EZIP) Home Office
y6 reduced IP variant(c800)

z
z managed modems

0-9
40 40 bit encryption
56 56 bit encryption
56i 56 bit encryption with IPSEC

　

Obsolete
h reduced desktop subset (SNMP, IP RIP/IGRP/EIGRP, Bridging,
ISDN, PPP, IPX, Atalk) 1003/4
h reduced desktop subset (SNMP, IP RIP/IGRP/EIGRP, Bridging,
WAN - X.25, IPX, Atalk) 1005