In this section:


SBC SWe Lite Call Performance

The table below includes the maximum call performance numbers for the listed call flow.

Note: For details on calculating DSP Requirements and determination of VM attributes to host the SBC SWe Lite, refer to Calculating DSP Requirements for SBC SWe Lite.


Call Performance - KVM, VMware, Microsoft Hyper-V On-Premises Deployments


SWe Lite Virtual Machine Resources, applicable to all supported hypervisors (KVM, VMware® Microsoft Hyper-V)Maximum SIP
with corresponding 
RTP Media Sessions1
SIP Signaling Session LimitsRTP Media Session LimitsMaximum Call Rate Setup (CPS)
Media Manipulation Mode2 (Requires Virtual DSP Intervention) Proxy Media Mode (No Virtual DSP Intervention)Audio/Video Streams 3
vCPU #GB RAM Maximum TCP/TLS-based SIP↔SIP Signaling Sessions7 Maximum SIP Registrations (60 minute refresh rate) No transcode, with in-band services scenario8 Default scenario: G.711/G.729ab RTP ↔ G.729ab/G.711SRTP, with in-band services9 Encryption services: G.711 RTP ↔ G.711 SRTP8 No encryption services: RTP ↔ RTP/SRTP ↔ SRTP10
11 GiB1003001000100100300 6 300 6 2510
21.5 GiB1000100010002002001000 6 1000 6 5010
42.5 GiB10001000 4 /600 5 5000450 4 /600 5 450 4 /600 5 1000 6 1000 6 10010
102.5 GiB1000 1200   5000   1200     1200   1200   1200   10010

1 Maximum number of concurrent sessions. The number assumes that calls are made using RTP/SRTP Proxy mode, or a mix of RTP/SRTP Proxy, media manipulation and video calls.

2 Maximum number of concurrent sessions with virtual DSP intervention. See Transcoding Capacity below for details.

3 Maximum number of concurrent audio/video sessions. The total system capacity is affected if A/V calls are introduced into the call mix. Maximum number of calls is reduced by the number of video streams used. For example, 1 vCPU instance processing 25 A/V calls has a total capacity of:  300 (max number of calls) - 25 (calls processed with 1 vCPU instance) = 275 calls.

4 Maximum number of concurrent sessions (when virtual DSP intervention is applied to 450 sessions) is 1000.

5 Maximum number of concurrent sessions (when virtual DSP intervention is applied to 600 sessions) is 600.

6 Maximum number of proxy media mode concurrent sessions is reduced by a count equivalent to the active number of concurrent RTP media manipulation sessions. Refer to note 1.

7 Supported by *-SG/*-SGX/*-SP licenses. 

8 Supported by *-SGX/*-SP licenses.

9 Supported only by *-SP licenses.

10 Supported by -SGX/-SG/-SP. See "SIP Signaling & RTP Direct Media/RTP Proxy Sessions without Encryption Services" in Working with Licenses.

Modified: for 8.1.5

Call Performance - Microsoft Azure Cloud


Azure Virtual Machine (VM) ResourcesMaximum SIP
with corresponding 
RTP Media Sessions1
SIP Signaling Session LimitsRTP Media Session LimitsMaximum Call Rate Setup (CPS)

Media Manipulation Mode2 (Requires Virtual DSP Intervention) Proxy Media Mode (No Virtual DSP Intervention)
VM InstancevCPU Maximum TCP/TLS-based SIP↔SIP Signaling Sessions4 Maximum SIP Registrations (60 minute refresh rate) No transcode, with in-band services scenario5 Default scenario: G.711/G.729ab RTP ↔ G.729ab/G.711SRTP, with in-band services6 Encryption services: G.711 RTP ↔ G.711 SRTP5 No encryption services: RTP ↔ RTP/SRTP ↔ SRTP4
B1ms11010100101010 3 10 3 10
B2s2 100 100 5003030 100 3 1003 10
 DS1_v21 300 300 1000100100 300 3 300 3 10
DS3_v24 1000 1000 5000400400500 3 1000 3 10

1 Maximum number of concurrent sessions. The number assumes that calls are made using RTP/SRTP Proxy mode, or a mix of RTP/SRTP Proxy, media manipulation and video calls.

2 Maximum number of concurrent sessions with virtual DSP intervention. See Transcoding Capacity below for details.

3 Maximum number of proxy media mode concurrent sessions is reduced by a count equivalent to the active number of concurrent RTP media manipulation sessions. Refer to note 1.

4Supported by -SG-CLOUD/-SGX-CLOUD/-SP-CLOUD licenses. 

5 Supported by -SGX-CLOUD/-SP-CLOUD licenses.

6 Supported by -SP-CLOUD license.



Number of RTP Port Pairs must be increased above maximum call capacity

The number of RTP Port Pairs must be configured slightly larger than the actual number of ports required to support the projected number of calls. We recommend you over-allocate the number of port pairs by approximately 25 - 30% above the number of calls you want to support. For details, see Configuring the Media System.

Call Capacity Limitations
  • Call capacity is limited to 4 calls per second when Info level logging is enabled. Additional logging verbosity reduces the call capacity.
  • Although the call setup rate is 10 calls per second, if Call Admission Control (CAC) is enabled, calls over the rate limit will be rejected with the message 480 Temporary Not Available.

Transcoding Capacity

The table below indicates the supported codecs and the maximum number of concurrent transcoded calls for specific codec combinations and system size. For the supported code list, refer to Protocols and Functions Supported.


Transcoding Capacity - KVM, VMware, Microsoft Hyper-V On-premises Deployments (1vCPU, 2vCPU, 4vCPU)

Transcoding Capacity - KVM, VMware, Microsoft Hyper-V On-premises Deployments (1, 2, 4 vCPU)

Transcoding ScenarioVirtual Machine vCPU Count
CODEC 1CODEC 21 vCPU2 vCPU4 vCPU
G.711A-law or G.711u-lawG.711A-law or G.711u-law100200600
G.711A-law or G.711u-lawG.72380160480
G.711A-law or G.711u-lawG.726 or G.729100200600
G.711A-law or G.711u-lawAMR WB3876225
G.711A-law or G.711u-lawOpus2454165
G.711A-law or G.711u-lawT.3850100300

Transcoding Capacity - KVM, VMware, Microsoft Hyper-V On-premises Deployments (10 vCPU)

Transcoding Capacity - KVM, VMware, Microsoft Hyper-V On-premises Deployments (10 vCPU)

CODEC 1CODEC 210 vCPU
G.711A-law or G.711u-lawG.711A-law or G.711u-law1200
G.711A-law or G.711u-lawG.7291200
OpusG.711A-law/mu-law360


Transcoding Capacity - Microsoft Azure Cloud Deployments

Transcoding Capacity - Microsoft Azure Cloud Deployments

Transcoding ScenarioMicrosoft Azure VM Instance
CODEC 1CODEC 2B1MS VMB2S VMDS1_v2DS3_v2
G.711A-law or G.711u-lawG.711A-law or G.711u-law1030100400
G.711A-law or G.711u-lawG.726 or G.7291030100400

SILK Capacity

The SBC Edge supports the SILK audio codec. Skype designates SILK as an internet wideband audio codec for use in VoIP. SILK operates at two different sampling rates: 8000 Hz narrowband and 16,000 Hz wideband (see the SILK Bandwith Options table). These rates allow for the capture of higher frequencies, which provide fuller sound, while also allowing interoperability with the Public Switched Telephone Network (PSTN). SILK has Low Bit Rate Redundancy (LBRR), also called Forward Error Correction (FEC), which protects the SBC Edge against packet loss.

The network bit rate of SILK is adaptive within the range that the following table specifies. The SBC Edge defines and modifies the average network bit rate in real-time, while the actual bit rate depends on the input signal and change over time. The bit rate can dynamically change within that range. Since all other parameters are equal, the higher bit rates result in higher audio quality.

SILK Bandwidth Options

Audio BandwidthFrequency (Hz)Bit Rate (KBPS)Description

Narrowband

80006 - 20
The SBC Edge only uses the narrowband mode either to interface to PSTN networks, or on low-end devices that support 8000 Hz or less sampling frequency.

Wideband

16,0008 - 30
The SBC Edge uses the wideband mode for all IP platforms that support 16,000 Hz or less sampling frequency.

The following tables outline the SILK performance and capacity.

SILK Performance for Microsoft Azure Cloud Deployments

The following table outlines the SILK performance numbers for Microsoft Azure Cloud deployments.

SILK Performance for Microsoft Azure Cloud Deployments

Transcoding ScenarioMicrosoft Azure VM Size
B1msB2sDS1_v2DS3_v2
SILKNB SRTP -> G711U RTP103095400
SILKNB SRTP -> G729A RTP103050300
SILKNB SRTP -> SILKWB RTP103035200

SILK Performance for On-premises Deployments

The following table outlines the SILK performance numbers for  On-premises deployments.

SILK Performance for On-premises Deployments

CodecVirtual Machine vCPU Count
1 vCPU2 vCPU4 vCPU
SILK-WB-G711U55135340
SILK-WB-G7293595230
SILK-WB-SILK-NB3588215
SILK-NB-G711U95200595
SILK-NB-G72950130325
G711U-SILK-NB

95

200595
G729-SILK-NB50130325
SILK-NB-WB3588215



SBC SWe Lite Single Instance Capacities

The SBC SWe Lite supports the following maximum configuration.

SBC SWe Lite Maximum Configuration Values

Feature

Maximum supported

Number of Signaling Groups

100

Cumulative number of channels* across all the Signaling Groups

1000 (1 vCPU)

4000 (2 vCPU, 4 vCPU, or 10 vCPU)

Call Route Tables100

Call Route Entries (all Call Route Tables combined)

1000

Static Routes1024

Registrar Table entries

1000 (1 vCPU, 1 GiB)
5000 (2 vCPU, 1.5 GiB)
5000 (4 vCPU or 10 vCPU, 2.5 GiB)

Contact Registrant Table entries

1000

Transformation Tables50

Transformation Table entries

1000

Media Profiles entries

20

Callback Number Tables80
Callback Numbers (in Callback Numbers List)16
SIP Server Table entries40
IP/FQDN or DNS-SRV entries (within each SIP Server Table entry)99
SIP Message Rule Tables100
(32 SIP Message Rules per Table)
SIP Profiles100

*A SIP Channel is a Signaling Group (SG) logical attribute used to represent a potential path for a SIP session (call) leg between the SBC and the remote peer associated with the SG. The SIP channel is not synonymous with a SIP session; the number of SIP channels may equal or exceed the number of supported maximum SIP sessions.

Call Forking

The SBC SWe Lite supports local call forking for up to eight separate destinations. Additionally, the SBC SWe Lite supports up to 20 early dialog responses and 20 calls forked downstream.

SIP Session Licensing

A SIP session for licensing purposes ('SIP session license") is a call (audio/audio+video) under SBC direction. Details are as follows:

  • A SIP session is a SIP transaction that establishes a bi-directional audio/video media exchange (RTP media stream) between two ports on the SBC or directly between two SIP endpoints.
  • SIP sessions are established by the SBC when the system has recognized the availability of SIP session license "tokens" in the SIP session license token pool.
  • SIP session license tokens are added to the pool when a SIP session license has been successfully applied to the SBC. For example, the SBC-1K-LIC25SIP license adds 25 SIP session license tokens to the SBC SIP session license pool.
  • To set up the call, the SBC grabs a license token from the purchased SIP session license pool, sets up the call for the bi-directional RTP media stream, and then releases the license token after the call is taken down.
  • The media does not have to actually flow through the SBC; the license token is still grabbed to set up the media flow, whether or not the media physically transits the SBC.
  • It is possible to consume more than one SIP session license during a single call between two SIP clients. For example, a call that "hairpins" (i.e., one pair of ports supports one RTP media stream through the SBC, and another pair supports a second media stream through the SBC) will consume two SIP session licenses.

SIP transactions that are not directly related to a call setup/tear down are not licensed through the SIP session licenses. Generally, these transactions are free (e.g., SUBSCRIBE, etc.) except when they fall under a chargeable feature. For example, the SBC supports SUBSCRIBE method pass through related transactions (For example, one SIP client to inform another that a message is waiting, etc.) in a way that is limited by available CPU resources, and not by licenses.

Burst Behavior

If multiple calls arrive simultaneously, the SBC SWe Lite will service the calls until it reaches a CPU usage threshold (configured raise TCA threshold).

Although TCA can be configured, Ribbon strongly recommends using the default configuration and not changing the default levels. For details on TCA, refer to Working with Historical Data and TCA Thresholds.

  • When the threshold is reached,  the SBC SWe Lite will reject calls until it reaches a "safe" level (configured clear TCA threshold).
  • When the "safe" level is reached, the SBC SWe Lite will begin accepting new calls.


RTP Media Services Supported

 For details on supported RTP media services and licensing requirements, please refer to Calculating Virtual Machine Requirements for an SBC SWe Lite.

System Concepts and Terminology

For details on system concepts and terminology, refer to Calculating Virtual Machine Requirements for an SBC SWe Lite.