gcm-request-2.txt

Variables starting with $ are values that i censored. documented below

POST https://android.clients.google.com/c2dm/register3 HTTP/1.1
Authorization: AidLogin $androidId:$securityToken
app: com.tellm.android.app
Gcm-ver: 11055448
Gcm-cert: a4a8d4d7b09736a0f65596a868cc6fd620920fb0
User-Agent: Android-GCM/1.5 (HWFRD HUAWEIFRD-L09)
content-length: 1209
content-type: application/x-www-form-urlencoded
Host: android.clients.google.com
Connection: Keep-Alive
Accept-Encoding: gzip

X-subtype=425112442765&
X-X-subscription=425112442765&
X-X-subtype=425112442765&
X-app_ver=1001800&
X-kid=%7CID%7C1%7C&
X-osv=24&
X-sig=[b64 encoded, length 343]&
X-cliv=1&
X-gmsv=11055448&
X-pub2=[b64 encoded, length 393]&
X-X-kid=%7CID%7C1%7C&
X-appid=c8GItStsCZY&
X-scope=*&
X-subscription=425112442765&
X-gmp_app_id=1%3A425112442765%3Aandroid%3A2f4503e0808c2362&  # this is the value google_app_id from strings.xml
X-app_ver_name=4.48.0&
app=com.tellm.android.app&
sender=425112442765&
device=$androidId&
cert=a4a8d4d7b09736a0f65596a868cc6fd620920fb0&
app_ver=1001800&
gcm_ver=11055448

token=|ID|1|:c8GItStsCZY:$token

$androidId and $securityToken are device/account specific values issued by google play.
The two requests differ in the X-scope value and in X-gmp_ver_name. X-sig and X-pub2 are the same across both requests. The $token is 
different in both requests.