Specifications

Chapter 4 Voice and IP Communications
4-20
Cisco Survivable Remote Site Telephony (SRST)
Cisco Survivable Remote Site Telephony (SRST)
Cisco SRST provides key backup telephony functions at remote branch office routers if
connectivity to the centrally-located Cisco CallManager fails (i.e. WAN link is interrupted).
In this case the Cisco SRST-enabled router will take over and provide robust telephony
service (including off-net calls to 911). It is ideal for enterprise organizations looking to
cost-effectively deploy IP telephony in their branch office location. SRST v3.2 with
12.3(11)T is available on Cisco 1751V, 1760V, 2600-XM, 2691, 2800 , 3725/3745, and 3800
series of routers.The Cisco Communications Media Module and the Cisco 7200 also support
previous versions of SRST.
Key Features
• SRST 3.2 features: Increased Phone support from 480 upto 720 phones; RFC2833
support for SCCP-SIP (vmail) DTMF conversion during SRST; External MOH from
live feed; SRST alias command increase from 10 to 50 (Set non registered DN's to call
forward on busy/NA); Call Pickup Ringing Extension; COR list increase from 10 to 20;
Option to disable H225 TCP keep alive timer to maintain calls during WAN failure
(new with 12.3(7)T)
• SRST 2.1 features: International language support; Call forward no-answer/busy to
Unity server with Personal Greeting; Cisco 7914 and 7935 support; VG248 support
• SRST 2.0 features: Huntstop support; Music/Tone on Hold; Class of Restriction;
Distinctive Ringing; Global forwarding to voicemail across PSTN during Cisco
CallManager fallback; TCL based simple AA and IVR on local gateway (SRS
Telephony router); Transfer across H323 network of Cisco endpoints; Alias lists for
single number to be designated for unregistered phones.
Selected Part Numbers and Ordering Information
For More Information
See the Cisco SRS Telephony Web site: http://www.cisco.com/go/srs
SRST 3.2 Platform Density and Feature License Part Numbers
Platform Number of Phones Supported Part Number Part Number (Spare)
Cisco 1751V, 1760V, 2801 Up to 24 phones FL-SRST-SMALL FL-SRST-SMALL=
Cisco 261x-XM, 262x-XM,
2811
Up to 36 phones FL-SRST-36 FL-SRST-36=
Cisco 265xXM, 2821 Up to 48 phones FL-SRST-MEDIUM FL-SRST-MEDIUM=
Cisco 2691 Up to 72 phones FL-SRST-SMALL and
FL-SRST-MEDIUM
FL-SRST-SMALL= and
FL-SRST-MEDIUM=
Cisco 2851 Up to 96 phones FL-SRST-96 FL-SRST-96=
Cisco 3725 router Up to 144 phones FL-SRST-144 FL-SRST-144=
Cisco, 3745, 7200 NPE300/400 Up to 240 phones FL-SRST-240 FL-SRST-240=
Cisco 3825 Up to 336 phones FL-SRST-336 FL-SRST-336 =
Cisco 7200NPE400/G1 Up to 480 phones FL-SRST-480 FL-SRST-480=
Cisco 3845 Up to 720 phones FL-SRST-720 FL-SRST-720=
SRST bundles
CISCO2801-SRST/K9 Feature License FL-SRST-SMALL: 8 G.711 channels of DSPs included
CISCO2811-SRST/K9 Feature License FL-SRST-36: 16 G.711 channels of DSPs included
CISCO2821-SRST/K9 Feature License FL-SRST-MEDIUM : 32 G.711 channels of DSPs included
CISCO2851-SRST/K9 Feature License FL-SRST-96: 48 G.711 channels of DSPs included
CISCO3825-SRST/K9 Feature License FL-SRST-168 : 64 G.711 channels of DSPs included
CISCO3845-SRST/K9 Feature License FL-SRST-240: 64 G.711 channels of DSPs included
CISCO1760-V-SRST Feature License FL-SRST-SMALL: 4 G.711 channels of DSPs included
CISCO2651XM-V-SRST Feature License FL-SRST-MEDIUM : 30 G.711 channels of DSPs included