Expressway B2B Video only 384 kbps call rate

[r.rung]

Hello Community,

i have cucm version 11.5(1)SU3, (CMS: 2.2.8, Expressways: X8.10.2)

the region settings are note configured and the "Default Interregion Max Video Call Bit Rate (Includes Audio)" Service Parameter is 6000.

now when i have a SIP B2B Call incoming or outgoing (CUCM->Expressway-C->Expressway-E->Internet) i always get 384 kbps as a call rate which is very low. From other customers i get much more to the same destination.

now when i make a SIP B2B Call to Skype for Business Cloud (CUCM->Expressway-C->CMS->Expressway-C->Expressway-E->Internet): i get a call rate of 2000 kpbs

when i make a call to CMS (CUCM->Expressway-C->CMS) i also get 2000 kpbs.

i tried a lot of older Expressway-Versions which make no different here. so i assume it is a CUCM Bug, but i can't find a Bug id?

[Andrew West]

Do you have any locations applied in UCM that are limiting your bandwidth?

[r.rung]

Yes I have locations in place but they allow 12000 kbps for video

[Mohammed al Baqari]

Hi,

If you trace the call from cucm rtmt, what is the bw modifer negotiated during the call setup and which entity is forcing 384kbps. 

CUCM will use the following rules to select the video bandwidth to be used during the call and communicated to endpoints in bandwidth modifiers:

• When CUCM receives an Offer or Answer from an endpoint, it checks whether there is a session level bandwidth modifier in the SDP:
• If there is a session level bandwidth modifier, CUCM retrieves the bandwidth value from the modifier. If there is more than one modifier type, it retrieves the modifier in the following order of preference: Transport Independent Application Specific (TIAS), Application Specific (AS), Conference Total (CT).
• If there is no session level bandwidth modifier, CUCM retrieves the bandwidth value from the sum of the media level bandwidth modifiers (e.g audio + video + bfcp video + fecc video).
• The allocated bandwidth is the maximum of what the two endpoints support. If the maximum bandwidth is higher than Region Bandwidth, CUCM will replace the advertised value to the endpoints with the value in the region and the allocated bandwidth will be the region bandwidth. If the maximum advertised bandwidth is lower than region bandwidth, CUCM will use the maximum advertised bandwidth.
• The selected bandwidth (whether region based or endpoint based) will be evaluated against E-LCAC. If the bandwidth (audio + video) is available, it will be deducted from the location and the call will proceed.  Else, the call will be dropped, retried as audio or AAR depending on the configuration

[r.rung]

Ok thanks i will Check that.

[r.rung · Accepted solution]

ok so this is what i can see.

this is an outgoing call:

Telepresence EX90 -> CUCM -> Expressway-C ->Expressway-E -> external SIP Plattform

the invites are without SDP, on Expressway-E i see:

incoming 200 OK with SDP:

 v=0
 o=Acano 0 0 IN IP4 192.168.x.x
 s=-
 c=IN IP4 193.x.x.x
 b=AS:4000
 t=0 0
 m=audio 37426 RTP/AVP 108 107 96 109 110 9 99 111 100 104 103 0 8 15 102 18 13 118 101
 b=TIAS:256000
 %a lot of codecs%
 m=video 37428 RTP/AVP 97 116 114 96 34 31 100 121
 b=TIAS:3744000
 %a lot of codecs%
 m=video 37430 RTP/AVP 97 116 114 96 34 100 121
 b=TIAS:4000000
  a=content:slides
 a=sendrecv
%a lot of codecs%
 m=application 37434 UDP/UDT/IX *
 
 then i see a 200 OK Send to Expressway-C with:

 v=0
 o=CiscoSystemsCCM-SIP 1560368 1 IN IP4 192.x.x.x
 s=SIP Call
 c=IN IP4 192.x.x.x
 b=AS:384
 t=0 0

i found out that someone put a Bandwidth PIPE Config with this limit :(

works now, could not imagine that it is simple as that, because calls to skype for business work with 2000 kpbs, nice to know that these calls completely ignore bandwith settings ;-)

[Mohammed al Baqari]

Great News. *Please remember to rate useful posts*