Username mismatch

I do not understand where to look to correct this error. It’s either in the extension or in the Polycom, but I cannot see it.

I see in the Authorization there is a trailing space in the Digest username. Does this come from the Polycom device or from the Asterisk extension? I use the WebGUI to configure the Polycom and it doesn’t appear there is a trailing space in the Auth User ID.

Any help?

<--- SIP read from UDP:192.168.10.105:5060 --->
REGISTER sip:192.168.10.38:5060 SIP/2.0
Via: SIP/2.0/UDP 192.168.10.105;branch=z9hG4bKf1fe0457EABED2E4
From: "100" <sip:[email protected]>;tag=768931B5-1302B7B2
To: <sip:[email protected]>
CSeq: 2 REGISTER
Call-ID: [email protected]
Contact: <sip:[email protected]>;methods="INVITE, ACK, BYE, CANCEL, OPTIONS, INFO, MESSAGE, SUBSCRIBE, NOTIFY, PRACK, UPDATE, REFER"
User-Agent: PolycomSoundPointIP-SPIP_550-UA/3.0.4.0061
Authorization: Digest username="100 ", realm="asterisk", nonce="1ea1582c", uri="sip:192.168.10.38:5060", response="8af76f9f8c02eabd6ecf1df183d0b03c", algorithm=MD5
Max-Forwards: 70
Expires: 600
Content-Length: 0

<------------->
--- (12 headers 0 lines) ---
Sending to 192.168.10.105:5060 (NAT)
[2014-10-15 10:06:07] WARNING[1944]: chan_sip.c:16376 check_auth: username mismatch, have <100>, digest has <100 >