Here's what I get with telnet set:
# set
AB_TEST='0'
ANNEX='B'
ANNEX_PTEST_FILE='ptest-results-0'
ANNEX_PTEST_HOST='192.168.178.20'
ANNEX_TEST='0'
CAPISERV_TEST='0'
CONFIG_AB_COUNT='2'
CONFIG_ACCESSORY_URL='http://www.avm.de/fritzbox_apps.php?hardware=93&oem=avm&language=de&country=&version=28.04.43&subversion='
CONFIG_ANNEX='B'
CONFIG_ASSIST='y'
CONFIG_ATA='y'
CONFIG_ATA_FULL='n'
CONFIG_AUDIO='n'
CONFIG_AURA='n'
CONFIG_BASIS='y'
CONFIG_BLUETOOTH='n'
CONFIG_BLUETOOTH_CTP='n'
CONFIG_BUTTON='y'
CONFIG_CAPI='y'
CONFIG_CAPI_MIPS='n'
CONFIG_CAPI_NT='n'
CONFIG_CAPI_POTS='y'
CONFIG_CAPI_TE='n'
CONFIG_CAPI_UBIK='n'
CONFIG_CAPI_XILINX='n'
CONFIG_CDROM='n'
CONFIG_CDROM_FALLBACK='n'
CONFIG_DECT='n'
CONFIG_DECT2='n'
CONFIG_DECT_ONOFF='n'
CONFIG_DSL='y'
CONFIG_ECO='y'
CONFIG_ENVIRONMENT='/var/env'
CONFIG_ENVIRONMENT_PATH='/proc/sys/urlader'
CONFIG_ETH_COUNT='1'
CONFIG_EXPERT='y'
CONFIG_FAX2MAIL='n'
CONFIG_FAXSUPPORT='n'
CONFIG_FIRMWARE_URL='http://www.t-com.de/downloads'
CONFIG_FON='y'
CONFIG_FONBOOK2='n'
CONFIG_FONGUI2='n'
CONFIG_FONQUALITY='y'
CONFIG_FON_HD='y'
CONFIG_HOMEI2C='n'
CONFIG_HOSTNAME='fritz.box'
CONFIG_I2C='n'
CONFIG_IGD='n'
CONFIG_INSTALL_TYPE='ar7_4MB_1eth_2ab_pots_wlan_28776'
CONFIG_IPONE='n'
CONFIG_JFFS2='n'
CONFIG_KIDS='y'
CONFIG_LED_NO_DSL_LED='n'
CONFIG_LIB_MATH='y'
CONFIG_LOGD='n'
CONFIG_MAILER='y'
CONFIG_MAILER2='n'
CONFIG_MEDIACLI='n'
CONFIG_MEDIASRV='n'
CONFIG_NAND='n'
CONFIG_NFS='n'
CONFIG_NQOS='n'
CONFIG_OEM_DEFAULT='avm'
CONFIG_PRODUKT='Fritz_Box_SpeedportW501V'
CONFIG_PRODUKT_NAME='FRITZ!Box Fon WLAN Speedport W 501V'
CONFIG_RAMSIZE='16'
CONFIG_RELEASE='1'
CONFIG_ROMSIZE='4'
CONFIG_SAMBA='n'
CONFIG_SERVICEPORTAL_URL='none'
CONFIG_SQLITE='n'
CONFIG_SRTP='n'
CONFIG_STOREUSRCFG='y'
CONFIG_SUBVERSION=''
CONFIG_SWAP='n'
CONFIG_T38='n'
CONFIG_TAM='n'
CONFIG_TAM_MODE='0'
CONFIG_TR064='n'
CONFIG_TR069='n'
CONFIG_UBIK2='n'
CONFIG_UNIQUE_PASSWD='n'
CONFIG_UPNP='n'
CONFIG_USB='n'
CONFIG_USB_HOST_AVM='n'
CONFIG_USB_HOST_TI='n'
CONFIG_USB_PRINT_SERV='n'
CONFIG_USB_STORAGE='n'
CONFIG_USB_STORAGE_USERS='n'
CONFIG_USB_WLAN_AUTH='n'
CONFIG_VDSL='n'
CONFIG_VERSION='04.43'
CONFIG_VERSION_MAJOR='28'
CONFIG_VLYNQ='y'
CONFIG_VLYNQ0='3'
CONFIG_VLYNQ1='0'
CONFIG_VLYNQ_PARAMS='vlynq_reset_bit_0'
CONFIG_VPN='n'
CONFIG_WEBSRV='y'
CONFIG_WLAN='y'
CONFIG_WLAN_1130TNET='n'
CONFIG_WLAN_1350TNET='y'
CONFIG_WLAN_GREEN='n'
CONFIG_WLAN_IPTV='n'
CONFIG_WLAN_MADWIFI='n'
CONFIG_WLAN_OPENWIFI='n'
CONFIG_WLAN_SAVEMEM='n'
CONFIG_WLAN_TCOM_PRIO='n'
CONFIG_WLAN_TXPOWER='n'
CONFIG_WLAN_WDS='y'
CONFIG_WLAN_WMM='n'
CONFIG_WLAN_WPS='n'
CONFIG_XILINX='y'
Country='049'
DISABLE_WLAN='0'
EXTERNAL_BOX_PARAMS='hardware=93&oem=avm&language=de&country=&version=28.04.43&subversion='
HOME='/'
HWRevision='93'
HWRevision_ATA='0'
HWRevision_BitFileCount=''
HWRevision_Reserved1='0'
IFS='
'
Language='de'
MANUAL_TZ_ENABLED='no'
OEM='avm'
OEM_DEFAULT_INDEX=''
OEM_tmp='avm'
PATH='/bin:/usr/bin:/sbin:/usr/sbin'
PPID='625'
PS1='# '
PS2='> '
PS4='+ '
PTEST_SERVER='192.168.178.20'
PWD='/'
SHELL='/bin/sh'
STATUS_TEST='0'
TERM='vt102'
TZ='CET-1CEST-2,M3.5.0/02:00:00,M10.5.0/03:00:00'
USB_HOST_TEST='0'
USER='root'
VERBOSE_RC_CONF='y'
WLAN_CAL='0'
WLAN_TEST='0'
_='/sbin/avmlogd'
annex='A'
enable_ata='0'
i='93'
idle='4'
item_count='2'
prevlevel='N'
reset_status='0'
runlevel='S'
tty='/dev/pts/0'
wlan_cal='03F4,03F1,0012,00E7,010A,00FC,010A,02E9,033B'
#